### 11th Standard CBSE Chemistry Study material & Free Online Practice Tests - View Model Question Papers with Solutions for Class 11 Session 2019 - 2020 CBSE [ Chapter , Marks , Book Back, Creative & Term Based Questions Papers - Syllabus, Study Materials, MCQ's Practice Tests etc..]

#### 11th Standard CBSE Mathematics Public Exam Model Question 2020 - by Ashutosh Saran - Gurgaon - View & Read

• 1)

One mole of CO2 contains

• 2)

de Broglie equation is

• 3)

The highest ionization energy is exhibited by

• 4)

The axial overlap between the two orbitals leads to the formation of a:

• 5)

Which of the following is the correct mathematical relation for Charles law at constant pressure?

#### 11th Standard CBSE Chemistry Public Exam Sample Question 2020 - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How many grams are contained in 1 gram atom of Na?

• 2)

The orbital with n = 3 and 1 = 2 is

• 3)

What is the electronic configuration of the elements of group 14?

• 4)

Which one is diamagnetic among NO, NO and NO-?

• 5)

At constant temperature, the pressure of the gas is reduced to one-third, the volume

#### 11th Standard CBSE Chemistry Public Exam Important Question 2019-2020 - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The mass of an atom of nitrogen is

• 2)

In a sodium atom (atomic number = 11 and mass number = 23) and the number of neutrons is

• 3)

In halogens, which of the following, increases from iodine to fluorine?

• 4)

The species CO, CN- and N2 are

• 5)

Viscosity of a liquid is a measure of

#### 11th Standard Chemistry Board Exam Sample Question 2020 - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The empirical formula of sucrose is

• 2)

Cathode rays are deflected by

• 3)

Which of the following is arranged in order of increasing radius?

• 4)

The molecule Ne2 does not exist because

• 5)

With rise in temperature, the surface tension of a liquid

#### 11th Standard Chemistry Board Exam Model Question 2019-2020 - by Ashutosh Saran - Gurgaon - View & Read

• 1)

12 g of Mg will react completely with an acid to give:

• 2)

The energy needed to remove a single electron (most loosely bound) from an isolated gaseous atom is called

• 3)

In halogens, which of the following, increases from iodine to fluorine?

• 4)

Out of the following, intramolecular hydrogen bonding exists in

• 5)

The cleansing action of soaps and detergents is due to

#### CBSE 11th Chemistry - Public Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

3 L water is added to 2 L of 5 M HCl. What is the molarity of HCl in the resultant solution?

• 2)

Calculate the mass of a photon of wavelength 3.6 $\mathring { A }$  .

• 3)

Air contains about 99% of Nand O2 gases. Why do not they combine to form NO under the standard conditions? Standard Gibbs energy of formation of NO (g) is 86.7 kJ mol-1.

• 4)

what is the nature of 'photochemical smog'?

• 5)

What is the significance of wave function $\Psi$ in the Schrodinger wave equation?
What is an atomic orbital? Why $\Psi$ is called orbital wave function?

#### CBSE 11th Chemistry - Some Basic Concept of Chemistry Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

One mole of CO2 contains

• 2)

5.6 litres of oxygen at NTP is equivalent to

• 3)

12 g of Mg will react completely with an acid to give:

• 4)

The number of significant figures in 0.0101 is

• 5)

The mass of an atom of nitrogen is

#### CBSE 11th Chemistry - Full Syllabus One Mark Question Paper with Answer Key - by Ashutosh Saran - Gurgaon - View & Read

• 1)

One mole of CO2 contains

• 2)

5.6 litres of oxygen at NTP is equivalent to

• 3)

Which of the following has the highest mass?

• 4)

The number of significant figures in 0.0101 is

• 5)

The mass of an atom of nitrogen is

#### CBSE 11th Chemistry - Full Syllabus Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How many atoms of He are present in 52 $\mu$ of He?

• 2)

Insulin contains 4.5 % sulphur. Calculate the minimum molecular mass of sulphur.

• 3)

(i) A sample of drinking water was found to be severely contaminated with chloroform CHCL3 which is Carcinogenic in nature. The level of contamination was 15ppm (by mass).
(b) Determine the molarity of chloroform in the water in which the mole fraction of ethanol is 0.040

• 4)

Calcium carbonate reacts with aqueous HCI to give CaCL2 and CO2 according to the reaction given below CaCO3(s) + 2HCI(aq) $\longrightarrow$CaCl2(aq) + CO2(g) + H2O(l)
What mass of CaCl2 will be formed when 250 mL of 0.76 M HCI reacts with 1000 g of CaCO3 ? Name the limiting reagent. Calculate the number of moles of CaCL2 formed in the reaction.

• 5)

A neutral atom of an element has 2K, 8L and 5M electrons. Find out the following.
Valency of the element.

#### CBSE 11th Chemistry - Full Syllabus Four Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Convert the following into basic units.
15.5 $\mu s$

• 2)

Calculate
(5.7 x 10-5$\div$ (4.2 x 10-3)

• 3)

The density of 3 M solution of Na Cl is 1.25 g mL-1. Calculate molality of the solution.

• 4)

Assuming the density of water  to be 1g/cm3, calculate the volume occupied by one molecule of water.

• 5)

50.0 kg of ${ N }_{ 2 }(g)$ and 10.0 kg of ${ H }_{ 2 }(g)$ are mixed to produce $NH_{ 3 }(g)$formed. Identify the limiting reagent in the productuion of $NH_{ 3 }$ in this situation.

#### CBSE 11th Chemistry - Full Syllabus Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How many amny significant figures present in the following? "5005"

• 2)

Write the complete symbol for the atom with the given number (Z) and atomic mass (A). Z = 92, A = 233

• 3)

The quantum number of six electrons are given below. Arrange them in order of increasing energies. if any of these combinations(s) has/have the same energy lists. $n=4,l=1,{ m }_{ 1 }=0,{ m }_{ s }=+\cfrac { 1 }{ 2 }$

• 4)

With what 7'elocity must an electron travel so that its momentum is equal to that of a photon of wavelength = 5200 $\mathring { A }$ ?

• 5)

What do you understand by isoelectronic species? Name a species that will be isoelectronic with the following atom or ion. Ar

#### CBSE 11th Chemistry - Full Syllabus Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Convert the following into kg. "0.91 x 10-27 g( mass of electron)"

• 2)

If the concentration of glugose (C6H12O6) in blood is 0.9 g L-1, what will be the molarity of glugose blood?

• 3)

Express the following in SI unit. "5 feet 2 inch"

• 4)

How many oxygen atoms are there in 18 g of water?

• 5)

What would be IUPAC names and symbols for elements with atomic numbers 122,127,135,149 and 150?

#### CBSE 11th Standard Chemistry - The p-block Elements Five Marks Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

What are the allotropes?Sketch the structure of two allotropes of carbon namely diamond and graphite.What is the impact of structure on physical properties of two allotropes?

• 2)

What happens when borax is heated strongly?

• 3)

Complete the following reactions
$CO+{ H }_{ 2 }\xrightarrow [ ZnO,{ Cr }_{ 2 }{ O }_{ 3 } ]{ 200\quad atm,\quad 675K }$

• 4)

Complete the following reactions
${ CaCO }_{ 3 }(aq)+{ CO }_{ 2 }(excess)\longrightarrow$

• 5)

What happens when aluminium is treated with dilute NaOH?

#### CBSE 11th Standard Chemistry - Organic Chemistry: Some Basic Principles and Techniques Five Marks Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this compound is subjected to complete combustion.

• 2)

Explain why ${ \left( { CH }_{ 3 } \right) }_{ 3 }\overset { + }{ C }$ is more stable than ${ CH }_{ 3 }\overset { + }{ C } { H }_{ 2 }$ and $\overset { + }{ C } { H }_{ 3 }$is the least stable cation.

• 3)

Sohan was very upset from last few days when he came to know that his father is alcoholic (takes alcohol).He knows about the side effects of the alcohol so want to keep away his father from it.He decided to talk about this with his father.When he asked his father about it, he told him, that he is not alcoholic, only occasionally he takes it but of Sohan does not even want him to ever touch it.
What values are possessed by Sohan and his father?

• 4)

Give condensed and bond line structural formulas and identify the functional group(s) present, if any, for: (a) 2, 2, 4-Trimethylpentane (b) 2-Hydroxy-1, 2, 3 propanetricarboxylic acid (c) Hexanedial.

• 5)

Explain the terms inductive and electromeric effects. Which electron displacement effect explain the following correct orders of acidity of the carboxylic acids?
(a) Cl3CCOOH > Cl2CHCOOH > ClCH2COOH
(b) CH3CH2COOH > (CH3)2CHCOOH > (CH3)3C.COOH

#### 11th Standard CBSE Chemistry - Hydrocarbons Five Marks Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+.
(i) Chlorobenzene, 2, 4-dinitrochlorobenzene, p-nitrochlorobenzene
(ii)Toluene, $p-{ H }_{ 3 }C-{ C }_{ 6 }{ H }_{ 4 }-{ NO }_{ 2 },\\ p-{ O }_{ 2 }N-{ C }_{ 6 }{ H }_{ 4 }-{ NO }_{ 2 }$

• 2)

Write IUPAC names of the products obtained by the ozonolysis of the following compounds:
(i) Pent-2-ene (ii) 3, 4-Dimethylhept-3-ene (iii) 2-Ethylbut-1-ene (iv) 1-Phenulbut-1-ene.

• 3)

How will you convert benzene into
(i) p-nitrobromobenzene (ii) m-nitrochlorobenzene (iii) p-nitrotoluene (iv) acetophenone?

• 4)

Addition of HBr to propene yields 2-bromopropane, while in presence of benzoyl peroxide, the same reaction yields 1-bromopropane. Explain and give mechanism.

• 5)

How will you convert the following compounds into benzene?
(i) Ethyne (ii) Ethene (iii) Hexane.

#### 11th Standard CBSE Chemistry - Environmental Chemistry Five Marks Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

What is 'Acid Rain'? How is it harmful to the environment?

• 2)

What is photochemical smog? What are its effects? How can it be controlled?

• 3)

(a) Define eutrophication and pneumoconiosis.
(b) Write difference between photochemical and classical smog.

• 4)

Have you ever observed any water pollution in your area? What measures would you suggest to control it?

• 5)

Do you observe any soil pollution in your neighbourhood? What efforts will t=you make for controlling the soil pollution?

#### CBSE 11th Chemistry - Environmental Chemistry Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How is the temperature effected as we go up the earth's surface? Explain

• 2)

It is advised not to sleep in a closed room with burning coke angithi to warm up. Explain.

• 3)

Sonu and Nilesh were friends. In winters, one day when they were going to school at 10:00 am Sonu felt irritation in his eyes and throat. He was also unable to breath.
Nilesh immediately took him to a doctor. Doctor gave him the proper remdy. When he became well, Nilesh asked reason for this Doctor answered him satisfactorily.
(i) Can you guess what reason was given by the doctor for the illness of Sonu.
(ii) Why such kind of polluting atmospheric change occurs?
(iii) What should be done to prevent the formation of smog?
(iv) What values are possessed by Nilesh?

• 4)

How carbon monoxide acts as a poison for human beings?

• 5)

What is 'Acid Rain'? How is it harmful to the environment?

#### CBSE 11th Chemistry - Hydrocarbons Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which of the following compounds will show cis-trans isomerism?
(CH3)2C=CH-C2H5

• 2)

Which of the following compounds will show cis-trans isomerism?
CH2=CBr2

• 3)

Write chemical equations for the combustion reaction of the following hydrocarbons. (i) Butane (ii) Pentene (iii) Hexyne (iv) Toluene

• 4)

Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+.
(i) Chlorobenzene, 2, 4-dinitrochlorobenzene, p-nitrochlorobenzene
(ii)Toluene, $p-{ H }_{ 3 }C-{ C }_{ 6 }{ H }_{ 4 }-{ NO }_{ 2 },\\ p-{ O }_{ 2 }N-{ C }_{ 6 }{ H }_{ 4 }-{ NO }_{ 2 }$

• 5)

Write IUPAC names of the products obtained by the ozonolysis of the following compounds:
(i) Pent-2-ene (ii) 3, 4-Dimethylhept-3-ene (iii) 2-Ethylbut-1-ene (iv) 1-Phenulbut-1-ene.

#### CBSE 11th Chemistry - Organic Chemistry: Some Basic Principles and Techniques Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this compound is subjected to complete combustion.

• 2)

Explain why ${ \left( { CH }_{ 3 } \right) }_{ 3 }\overset { + }{ C }$ is more stable than ${ CH }_{ 3 }\overset { + }{ C } { H }_{ 2 }$ and $\overset { + }{ C } { H }_{ 3 }$is the least stable cation.

• 3)

Sohan was very upset from last few days when he came to know that his father is alcoholic (takes alcohol).He knows about the side effects of the alcohol so want to keep away his father from it.He decided to talk about this with his father.When he asked his father about it, he told him, that he is not alcoholic, only occasionally he takes it but of Sohan does not even want him to ever touch it.
What is the main constituent of alcoholic beverages?

• 4)

Sohan was very upset from last few days when he came to know that his father is alcoholic (takes alcohol).He knows about the side effects of the alcohol so want to keep away his father from it.He decided to talk about this with his father.When he asked his father about it, he told him, that he is not alcoholic, only occasionally he takes it but of Sohan does not even want him to ever touch it.
Write the IUPAC name and hybridization of this main constituent.

• 5)

Mr.Sing altered the amount of cheque and was caught by police. Chromatography is an important technique extensively used to separate a mixture into their components to purify compounds and also to test the purity of compounds. If any cheque is written in a particular ink and somebody else alters it with another ink, it can be detected with the help of chromatography.
What values are not possessed by Mr.Sing involved in forgery?

#### CBSE 11th Chemistry - The p-block Elements Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Among group 14 elements name
most metallic element

• 2)

Among group 14 elements name
the elements having tendency to from $p\pi -p\pi$ bonds.

• 3)

Carbon form covalent compounds whereas lead form ionic compounds.why?

• 4)

A colorless aqueous solution on adding water and on heating gave a white NH4Cl and NH4OH in excess resulted in the dissolution of some of the precipitate and a gelatinous precipitate is obtained.what is the hydroxide formed in aqueous solution?

• 5)

Aluminium dissolves in mineral acids and aqueous alkalies and thus shows amphoteric character.A piece of aluminum foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning matchstick near the mouth of the test tube, a pop sound indicates the evolution of hydrogen gas.The same activity when performed with concentrated nitric acid, reaction doesn't proceed, Explain the reason

#### CBSE 11th Chemistry - The s-Block Elements Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Explain why ?
The crystalline salts of alkaline earth metals contain more water of crystallisation than the corresponding alkali metal
salts.

• 2)

Dr.Sharma , cardiologist suggested his patienta to take more potassium ions for healthy heart. potassium ions are the most abundant cations within cell fluids, where they activate many enzymes, participate in the oxidation of glucose to pro duse ATP While sodiun ions are responsible for the transmission for nerve signals.
It  intake of potassium , harmful for our body?

• 3)

Dr.Sharma , cardiologist suggested his patienta to take more potassium ions for healthy heart. potassium ions are the most abundant cations within cell fluids, where they activate many enzymes, participate in the oxidation of glucose to pro duse ATP While sodiun ions are responsible for the transmission for nerve signals.
What are the sources of potassium ?

• 4)

Give the reson for following
Potassium carbonate cannot be prepared by Solvay ammonia process.

• 5)

Reema takes milk every day . She also take curd and other milk products.She takes green leafy vegitables and fruits also. An adult body contains about 25g of magnesium and 1200 g of calcium and 5 g of iron .these elements must be a part of our diet. All enzymes that utilize ATP in phosphate transfer required magnesium as co-factor. the main pigment for the absorption of light in plants is chlorophyll, which contains magnesium. were as Anita does not like milk and takes lot of junk food.

Why should we take green leafy vegitables in our dite?

#### CBSE 11th Chemistry - Hydrogen Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides.Write its reaction with ${ Al }_{ 2 }{ Cl }_{ 6 }$

• 2)

At the home of Mr.Kumar, Dalda ghee is generally used. He is suffering from high blood pressure and diabetes. Mr.Sharma, a friend of Mr.Kumar has advised him to change from ghee to vegetable oil like mustard oil.
Dihydrogen (H2) is used in the manufacture of vanaspati ghee by hydrogenation of polyunsaturated vegetable oils using nickel as a catalyst.
Vegetable oil $\xrightarrow [ { H }_{ 2 } ]{ Ni }$ vanaspati ghee
Should we use vegetable oils for cooking? why?

• 3)

In India, there is the shortage of drinking water. Thus, projects like rainwater harvesting are used by Green Park Association to increase the amount of underground water. Rainwater is the almost pure form of water after the heavy shower as it is, in fact, the distilled water. The first shower contains dissolved gases from the atmosphere. Being a good solvent, when it flows on the surface of the earth, it dissolves many salts in the form of hydrogen carbonate, chloride and sulphate in water which make it hard
Give the values possessed by the office bearer of Green Park Association?

• 4)

Scientist of UK has designed the cars, working on hydrogen fuel cells instead of petrol engines. Here hydrogen is used as sources of electrical energy i.e. a reaction of hydrogen and oxygen is used to generate electrical energy. It has many advantages over the conventional fossil fuels and electric power generation.
Give two advantages of hydrogen over fossil fuels?

• 5)

Scientist of UK has designed the cars, working on hydrogen fuel cells instead of petrol engines. Here hydrogen is used as sources of electrical energy i.e. a reaction of hydrogen and oxygen is used to generate electrical energy. It has many advantages over the conventional fossil fuels and electric power generation.
What are the values possessed by scientists of UK?

#### CBSE 11th Chemistry - Redox Reactions Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Justify that the reactions
4Na(s) + O2(g) $\rightarrow$ 2Na2O(s) are redox reactions.

• 2)

Given the standard electrode potentials, K+/K = -2.93V, Ag+/Ag = 0.80V, Hg2+/Hg = 0.79V, Mg2+ / Mg = -2.37V, Cr3+/Cr = -0.74V
Arrange these metals in their increasing order of reducing power.

• 3)

Identify the oxidant and reductant in each of the following reactions.
Zn(s) + 2H+(aq) $\rightarrow$ pb(s) + CO(g)

• 4)

Predict whether the following cell does exist or not?
Zn|Zn2+(1M)||Cd2+(1M)|Cd
Given,
$\left[ { E }_{ Zn,{ Zn }^{ 2+ } }^{ 0 }=0.76V \ and \ { E }_{ Cd,{ Cd }^{ 2+ } }^{ 0 }=0.40V \right]$

• 5)

Identify the redox reaction out of the following reactions and identify the oxidising and reducing in them.
3HCl(aq) + HNO3(aq) $\longrightarrow$ Cl2(g) +NOCl(g) + 2H2O(l)

#### 11th Standard CBSE Chemistry - Equilibrium Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which of the following reactions involve homogeneous equilibrium and which ones involve heterogeneous equilibrium?
$2{ NH }_{ 2 }(g)\rightleftharpoons { N }_{ 2 }(g)+3{ H }_{ 2 }(g)$

• 2)

Which of the following reactions involve homogeneous equilibrium and which ones involve heterogeneous equilibrium?
$2Cu({ NO }_{ 3 })_{ 2 }\left( s \right) \rightleftharpoons 2Cuo(s)+4{ NO }_{ 2 }(g)+{ O }_{ 2 }(g)$

• 3)

For the equilibrium, $2NOCl\left( g \right) \rightleftharpoons 2NO\left( g \right) +{ Cl }_{ 2 }\left( g \right)$ the value of the equilibrium constant, ${ K }_{ c }$ is $3.17\times { 10 }^{ -6 }$ at 1069 K.
Calculate the ${ K }_{ p }$ for the reaction at this temperature?

• 4)

Classify the following species into Lewis acids and Lewis bases and show how these act as BCl3

• 5)

K1 and K2 for dissociation of H2S are 4 x 10-7 and 1 x 10-5. Calculate sulphide ion concentration in 0.1M H2S Solution.

#### 11th Standard CBSE Chemistry - Chemical Bonding and Molecular Structure Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Give the geometry of (CH3)3N and [(CH3)3Si]3N state if they are isostructural?

• 2)

One day when Ravi was passing by his laboratory and felt some suffocating odour. He saw his laboratory attendant was preparing some chemical, named as ammonia. Suddenly, he saw that some chemical had fallen at the hand of the attendant. He run at once and take some highly diluted HCl and apply at the burned place.By this the attendent got relief.
Can you predict and draw the structures of these compound.Also mark the central atom and find out the bond pairs and lone pairs.

• 3)

Rahul, a brilliant science student, was very keen to do experiments and get knowledge from them. One day he took some sugar and salt separately and added some acid of sulfur (which is generally used for toilet cleaning) and notice the changes. He got confused as he expected that the reaction of salt should be faster. Next day he asked about his experiment to his science teacher, who clarity the reason for the result he got. He got satisfied.
Draw the electron dot structure of acid of sulphur and salt.

• 4)

Write the resonance structures for SO3, NO2 and NO-3

• 5)

Explain with the help of suitable example polar covalent bond.

#### 11th Standard CBSE Chemistry - State of Matter Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

On a ship sailing in Pacific ocean where temperature is $23.4^{ \circ }C$ , a balloon is filled with 2L air. What will be the volume of the balloon when the ship reaches Indian ocean, where temperature is  $26.1^{ \circ }C$ ?

• 2)

An iron cylinder contains helium at a pressure of 250 KPa at 300 K. The cylinder can withstand a pressure of $1\times { 10 }^{ 6 }Pa$ . The room in which cylinder is placed catches fire. Predict whether the cylinder will blow up before it melts or not (mp of the cylinder = 1800 K).

• 3)

Gases possess characteristic critical temperature which depends upon the magnitude of intermolecular forces between the gas particles. The critical temperature of ammonia and carbon dioxide are 405.5 K and 304.10 K respectively. Which of these gases will liquify first when you start cooling from 500 K to their critical temperature?

• 4)

Rainy season brings lots of happiness as well as lots of diseases also.Malaria, dysentery, jaundice are common diseases that occurred in this season.Children usually get affected by these diseases.Renu's teacher advised the class to drink boiled water.She also explained to test jaundice by doing a simple test based on the property of surface tension.She told them to take the urine sample in a glass and sprinkle the sulphur powder over it.If it floats, the test is negative but if it sinks, it is positive.After reading the above paragraph, answer the following questions.
What is the reason that sulphur powder floats if the test is negative but it sinks if it is positive?

• 5)

Rainy season brings lots of happiness as well as lots of diseases also.Malaria, dysentery, jaundice are common diseases that occurred in this season.Children usually get affected by these diseases.Renu's teacher advised the class to drink boiled water.She also explained to test jaundice by doing a simple test based on the property of surface tension.She told them to take the urine sample in a glass and sprinkle the sulphur powder over it.If it floats, the test is negative but if it sinks, it is positive.After reading the above paragraph, answer the following questions.
What values are expressed in the above paragraph.

#### 11th Standard CBSE Chemistry - Thermodynamics Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Calculate ${ \triangle }G^{ \ominus }$for the reaction
4NH3(g) + 5O2(g)$\longrightarrow$ 4NO(g) + 6H2O(l)
given that ${ \triangle }G^{ \ominus }$ for the formation of NH(g), NO(g) AND H2O (l) are - 16.8 KJ mol-1 +86.7 KJ mol-1 and -237.2KJ mol-1 respectively. predict feaibility of reaction under the conditions.

• 2)

Determine whether or not it is possible for sodium to reduce aluminium oxide to aluminium at 298 K.
$\triangle _{ f }G^{ \ominus } \ { Al }_{ 2 }{ O }_{ 3 }(s)=-1582 \ KJ \ { mol }^{ -1 };\triangle _{ f }G^{ \ominus }Na_{ 2 }O(s)=-377 \ KJ \ { mol }^{ -1 }$

• 3)

1 g of graphite is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atmospheric
pressure according to the equation C(graphite) + O2(g)$\longrightarrow$CO2 (g) During the reaction, temperature rises from 298 K to 299 K. If the heat capacity of the bomb calorimeter is 20.7kJ/K, what is the enthalpy change for the above reaction at 298 K and 1 atm?

• 4)

Calculate $\triangle _{ r }G^{ \ominus }$ for conversion of oxygen to ozone, 3/2 O2(g) $\rightarrow$ O3(g) at 298 Kp. If Kpfor this conversion is 2.47 x 10-29.

• 5)

Define the following:
(i) First law of thermodynamics.
(ii) Standard enthalpy of formation

#### 11th Standard CBSE Chemistry - The s-Block Elements Five Mark Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Name the groups which constitute s-block elements.

• 2)

Why is the density of potassium less than sodium ?

• 3)

What happens when K burns in air ? Give chemical equation.

• 4)

Starting with sodium chloride how would you proceed to prepare? sodium hydroxide

• 5)

Starting with sodium chloride how would you proceed to prepare?Sodium peroxide

#### 11th CBSE Chemistry - Hydrogen Five Mark Model Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

What do you expect the nature of hydrides is, if formed by elements of atomic numbers 15, 19, 23, 44 with dry dilhydrogen? Compare their behaviour towards water.

• 2)

How would you prepare dihydrogen from a substance other than water?

• 3)

What mass of hydrogen peroxide will be present in 2L of a 5M solution?

• 4)

Calculate the mass of oxygen which will be liberated by the decomposition of 200mL of this solution.

• 5)

Complete the following chemical reactions and classify the above into (a) hydrolysis,(b) redox and (c) hydration reactions.
$PbS(s)+{ 4 }H_{ 2 }{ O }_{ 2 }(aq)\rightarrow$

#### CBSE 11th Standard Chemistry - Redox Reactions Five Mark Model Questions - by Amit Pandya - Varanasi - View & Read

• 1)

Justify that the following reaction are redox reaction
$CuO(s)+{ H }_{ 2 }(g)\rightarrow Cu(s)+{ H }_{ 2 }O(g)$

• 2)

Justify that the following reaction are redox reaction
$4BCl_{ 3 }(g)+3LiAl{ H }_{ 4 }(s)\longrightarrow 2{ B }_{ 2 }{ H }_{ 6 }(g)+3LiCl(s)+3AlC{ l }_{ 3 }(s)$

• 3)

Justify that the following reaction are redox reaction
$2k(s)+{ F }_{ 2 }(g)\longrightarrow 2K^{ + }{ F }^{ - }(s)$

• 4)

Justify that the following reaction are redox reaction
$4N{ H }_{ 3 }(g)+5{ O }_{ 2 }(g)\longrightarrow 4NO(g)+6H_{ 2 }O(g)$

• 5)

Using electron transfer concept, identify the oxidant and reductant in the redox reaction.
Zn(s) +2H+(aq)$\rightarrow$ Zn2+(aq) +H2(g)

#### 11th CBSE Chemistry - Equilibrium Five Mark Model Questions - by Amit Pandya - Varanasi - View & Read

• 1)

Calculate degree of hydrolysis,

• 2)

Calculate the pH of a buffer which is 0.1 M in acetic acid and 0.15 M in sodium acetate. Given that the ionisation costants of acetic acid is 1.75 x 10-5. Also calculate the change in pH of the buffer if to 1L of the buffer 1 cc of 1 M NaOH are added.

• 3)

Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below.
Human muscle-fluid, 6.83

• 4)

The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8,5.0,4.2,2.2 and 7.8 respectively. Calculate the corresponding hydrogen ion concentration in each.

• 5)

On the basic of Le-Chatelier principle explain how temperature and pressure can be adjusted to increase the yield of ammonia in the following reaction.
${ N }_{ 2 }\left( g \right) +3{ H }_{ 2 }\left( g \right) \rightleftharpoons 2{ NH }_{ 3 }\left( g \right) \triangle H=192.38 \ KJ \ { mol }^{ -1 }$ What will be the effect of addition of argo to the above reaction mixture at constant volume?

#### CBSE 11th Chemistry - Classification of Elements and Periodicity in Properties Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The elements Z = 117 and 120 have not yet been discovered. In which family/group would you place these elements and also give the electronic configuration in each case.

• 2)

Calculate the electronegativity of carbon if EH-H = 104.2 kcal mol-1, EC-C =  83.1 kcal mol-1,EC-H = 98.8 kcal mol-1, X= 2.1.

• 3)

The first $({ \triangle }_{ i }{ H }_{ 1 })$ and the second $({ \triangle }_{ i }{ H }_{ 2 })$ ionization enthalpies (in kJ mol-1) and the $({ \triangle }_{ eg }H)$ electron gain enthalpy (in kJ mol-1 ) of a few elements are given below

 Elements ${ \triangle }_{ i }{ H }_{ 1 }$ ${ \triangle }_{ i }{ H }_{ 2 }$ ${ \triangle }_{ eg }H$ I 520 7300 -60 II 419 3051 -48 III 1681 3374 -328 IV 1008 1846 -295 V 2372 5251 +48 VI 738 1451 -40

Which of the above elements is likely to be
(i)   the least reactive element?
(ii)  the most reactive metal?
(iii)  the most reactive non-metal?
(iv)  the least reactive non-metal?
(v)   the metal which can form a stable binary halide of the formula MX2(X = halogen)?
(vi)  the metal which can form a predominantly stable covalent halide of the formula MX (X = halogen)?

• 4)

Arrange the following in decreasing order of their van der Waals' radii CI, H, O, N.

• 5)

Chemical reactivity of elements is highest at the two extremes of a period and is lowest in the center. Highly reactive elements do not occur in nature in free state, they usually occur in nature in free state, they usually occur in combined state. Some students are highly aggressive and keep on fighting with each other like highly reactive elements. Some students are sober and help each other and do not fight.
(i) Elements of which group are most reactive?
(ii) Which group elements are least reactive and why?
(iii) What are the harmful effects of being aggressive?
(iv) What values are possessed by sober people?
(v) Which kind of people pick up fight, while driving on the road in case of accidents? What are its consequences? What should we do?

#### 11th Standard CBSE Chemistry - Structure of Atom Four and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which state of the triple ionised beryllium $(Be^{ 3+ })$ has the same orbit radius at that of the ground state of hydrogen atom?

• 2)

The wavelength range of the visible spectrum extends from violet nm). Express these wavelengths in frequencies (Hz). (nm = 9 m)

• 3)

The number of electrons, protons and neutrons in a species are equal to 18, 16 and 16 respectively. assign the proper symbol o the species.

• 4)

The threshold frequency (vo ) for a metal is $7.0\times { 10 }^{ 14 }{ s }^{ -1 }$ . Calculate the kinetic energy of an electron emitted when radiation of frequency (v) = 1.0 x 1015 s-1 hits the metal.

• 5)

A golf ball has a mass of 40g and a speed of 25 m/s. If the speed can be measured within accuracy of 2%, calculate the uncertainty in the position.

#### 11th Standard CBSE Chemistry - Some Basic Concept of Chemistry Four Marks and Five Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Convert the following into basic units
25365 mg.

• 2)

At what temperature will both the Celsius and Fahrenheit scales read the same value ?

• 3)

A measured temperature on Fahrenheit scale is 200$^{ 0 }$ F. What will this reading be on Celsius scale ?

• 4)

Express the following in the scientific notation
(4.56 x 103 + 2.62 x 102)

• 5)

Express the following in the scientific notation
(9.87 x 10-3 - 2.26 x 10-4)

#### 11th Standard CBSE Chemistry - Environmental Chemistry Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What are pesticides and herbicides? Explain giving examples.

• 2)

How is the temperature effected as we go up the earth's surface? Explain

• 3)

What do you mean by ozone hole?What are its consequences?

• 4)

Sonu and Nilesh were friends. In winters, one day when they were going to school at 10:00 am Sonu felt irritation in his eyes and throat. He was also unable to breath.
Nilesh immediately took him to a doctor. Doctor gave him the proper remdy. When he became well, Nilesh asked reason for this Doctor answered him satisfactorily.
(i) Can you guess what reason was given by the doctor for the illness of Sonu.
(ii) Why such kind of polluting atmospheric change occurs?
(iii) What should be done to prevent the formation of smog?
(iv) What values are possessed by Nilesh?

• 5)

Explain the tropospheric pollution in 100 words?

#### CBSE 11th Chemistry - Hydrocarbons Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How do you account for theformation of ethane during chlorination of methane?

• 2)

For the following compounds, write structural formulas and IUPAC names for all possible isomers having the number of double or triple bond as indicated:
(a) C4H8 (one double bond)
(b) C5H8 (one triple bond)

• 3)

An alkene 'A' contains three C-C, eight C-H, $\sigma$-bonds, and one C-C $\pi$-bond. 'A' on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write the IUPAC name or 'A'.

• 4)

Why is benzene extra-ordinarily stable though it contains three double bonds?

• 5)

What are the necessary conditions for any system to be aromatic?

#### CBSE 11th Chemistry - Organic Chemistry: Some Basic Principles and Techniques Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Write down the formula of the first four members of each homologous series beginning with the following compounds.
${ CH }_{ 3 }CO{ CH }_{ 3 }$

• 2)

Write down the formula of the first four members of each homologous series beginning with the following compounds.
${ CH }_{ 3 }OH$

• 3)

Write down the formula of the first four members of each homologous series beginning with the following compounds.
$HC\equiv CH$

• 4)

Write dash, condensed and bond line structural formulae for the isomers of the molecular formulae.
(iii) C3H6O

• 5)

Draw formulae for the first five members of each homologous series beginning with the following compounds.
(iii) H-CH=CH2

#### CBSE 11th Chemistry - The p-block Elements Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A certain salt X, gives the results
Borax swells up to a glassy mass on strong heating.
Is swells up to a glassy material Y on strong heating

• 2)

Explain the following.
Aluminium forms [AlF6]3- ion but boron does not form [BF6]3-ion.

• 3)

Account for CO is poisonous.

• 4)

Account for CO2 is used in refrigeration.

• 5)

What are electron deficient compounds? Are BCl3 and SiCl4 electron deficient species? Explain

#### CBSE 11th Chemistry - The s-Block Elements Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Write the chemical formula Chile salt petre

• 2)

Compare the alkali metals and alkaline earth metals with respect to
(ii) basicity of oxides

• 3)

Present a comparative account of the alkali and akaline earth metals with respect to the following characteristics.
(ii) Nature of oxides and their solubility in water

• 4)

Present a comparative account of the alkali and akaline earth metals with respect to the following characteristics.
(iv) solubility of oxosalt

• 5)

Explain the Aluminium utensils should not be kept in water overnight

#### CBSE 11th Chemistry - Hydrogen Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

If 1kg of a hard water sample contains 12 mg of CaCl2 and 12mg of MgCl2, then what will be the total hardness in terms of CaCO3 Per 106 parts by mass of water sample.

• 2)

Write equations for the reactions
Peroxydisulphuric acid is hydrolysed.

• 3)

Calculate the volume strength of a 3% solution of ${ H }_{ 2 }O_{ 2 }$

• 4)

What are the advantages in using hydrogen as a fuel?

• 5)

Why is hydrated barium peroxide used in the preparation of hydrogen peroxide instead of anhydrous barium peroxide?

#### 11th Standard CBSE Chemistry - Redox Reactions Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Suggest a list of the substance where carbon can exhibit oxidation states from -4 to +4 and nitrogen from -3 to +5

• 2)

Write formulae for the compounds.
Mercury (II) chloride

• 3)

Write formulae for the compounds.
Chromium (III) oxide

• 4)

Whenever a reaction between an oxidising agent and a reducing agent is carried out a, compound of lower oxidation state is formed if the reducing agent is in excess and a compound of higher oxidation state is formed if the oxidation agent is in excess. Justofy this statement givng three illustrations.

• 5)

Identify the type of redox reaction taking place in the following
$2\overset { +1 }{ K } \overset { 5 }{ CI } \overset { -2 }{ O } _{ 3 }(s)\longrightarrow 2\overset { -1 }{ K } \overset { -1 }{ CI } (s)+3\overset { 0 }{ O } _{ 2 }(g)$

#### 11th Standard CBSE Chemistry - Equilibrium Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What is the minimum volume of water required to dissolved 1g of calcium sulphate at 298 K? (For calcium sulphate, Ksp is 9.1 x 10-6).

• 2)

The ionisation constant of acetic acid is ED 1.74 x 10-5. Calculate the degree of dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ion in the solution and its pH.

• 3)

An equilibrium mixture at 300K contains N2 O4 and NO2 at .28 and 1.1 atm pressure respectively. If the volume of the container is doubled, calculate the new equilibrium pressure of two gases.

• 4)

The ionisation constant of dimethylamine is 5.4 x 10-4. Calculate its degree of ionisation in its 0.02 M solution. What percentage of dimethylamine is ionised if the solution is also 0.1 M in NaOH?

• 5)

At 473K, equilibrium constant Kc for decomposition of phosphorus pentachloride Pcl5 is $8.3\times { 10 }^{ -3 }$ . If decomposition is depicted as,
${ PCl }_{ 5 }(g)\leftrightharpoons { PCl }_{ 3 }(g)+{ Cl }_{ 2 }(g);$
$\Delta H°=124.0 \ { kJmol }^{ -1 }$

What would be the effect on ${ K }_{ c }$ if (a) more PCl5   is added (b) pressure is increased (c) the temperatured in increased ?

#### 11th Standard CBSE Chemistry - Thermodynamics Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A man takes a diet equivalent to 10000 kJ per day and does work, in expending his energy in all forms equivalent to 12500 kJ per day. What is change in internal energy per day?If the energy lost was stored as sucrose (1632 kJ pre 100g), how many days should it take to lose 2kg of his weight?(Ignore water loss)

• 2)

The enthalpy of vaporization of liquid diethyl ether (C2H5)2O is 26.0 KJ mol-1 at its boiling point (35.0oC). Calculate $\triangle$So for the conversion of Liquid to vapour and

• 3)

Calculate the standard Gibbs energy change for the formation of propane at 298 K.
3 C (graphite) + 4H2(g) -> C3H8 (g)
$\triangle _{ f }{ H }^{ o }for\quad propane,{ C }_{ 3 }{ H }_{ 8 }(g)=270.2J{ K }^{ -1 }{ mol }^{ -1 }$
${ S }_{ m }^{ o }C(graphite)=5.70J{ K }^{ -1 }{ mol }^{ -1 }$
$and \ { S }_{ m }^{ 0 }{ H }_{ 2 }(g)=130.7J{ K }^{ -1 }{ mol }^{ -1 }$

• 4)

The molar heat of formation of NH4NO3 (s) is -367.54 kJ and those of N2 O(g) and H2O(i) are + 81.46 kJ and -258.78 kJ respectively at 25oC and 1.0 atmospheric pressure. Calculate $\Delta$H and $\Delta$U for the reaction.

• 5)

Justify the following statements.
Reaction with $\triangle$G< 0 always have an equilibrium constant greater than 1.

#### 11th Standard CBSE Chemistry - State of Matter Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Explain
The boiling point of a liquid rises on increasing pressure.

• 2)

Explain
The level of mercury in a capillary tube is lower than the level outside when a capillary tube inserted in the mercury.

• 3)

Tea or coffee is sipped from a saucer when it is quite hot.

• 4)

Calculate the total and average kinetic energy of 32 g methane molecules at 27oC(R = 8.314 JK-1 mol-1 )

• 5)

Nitrogen molecule(N2 )has radius of about 0.2 nm. Assuming that nitrogen molecule is spherical in shape, calculate volume of a single molecule of N2

#### 11th Standard CBSE Chemistry - Thermodynamics Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

An athlete is given 100g of glucose of energy equivalent to 1560 kJ. He utilises 50% of this gained energy in the event.In order to avoid storage of energy in the body, calculate the weight of water that would need to perspire.The enthalpy of vaporisation of water is 44 kJ mol-1.

• 2)

When 20.0 g of ammonium nitrate (NH4NO3) is dissolved in 125 g of water in a coffee cup calorimeter. (Treat heat capacity of water as the heat capacity of the calorimeter and its contents).

• 3)

A chemist while studying the properties of gaseous CCl2, a chlorofluorocarbon refrigerant, cooled a 1.25 g sample at a constant atmospheric pressure of 1.0 atm from 320 K to 293 K. During cooling, the sample volume decreased from 274 to 248 mL. Calculate $\Delta$H and $\Delta$U for the chlorofluorocarbon for this process. For CCl2F2, Cp = 80.7 J/(mol K).

• 4)

A cylinder of gas supplied by a company is assumed to contain 14kg of butane.If a normal family requires 20000kj of energy per day for cooking, how long will the cylinder last?

• 5)

If the air supplied to the burner is insufficient, a portion of gas escapes without combustion. Assuming that 25% of the gas is wasted due to this inefficiency, how long will the cylinder last (Heat of combustion of butane = 2658 kJ/mol)?

#### 11th Standard CBSE Chemistry - Chemical Bonding and Molecular Structure Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Arrange the following in increasing order of ionic character  and also give the reason.
NaCl, CaCl2, MgCl2, MgO.

• 2)

What is the hybrid state of
Be in BeCl2

• 3)

What is meant by linear combination of atomic orbitals?

• 4)

What is hydrogen bond? What requirements should a molecule fulfil for the formation of hydrogen bond? Explain the formation of hydrogen bond in HF and NH3 molecules. Discuss intramolecular hydrogen bond.

• 5)

Draw the molecular structures of  XeOF2
Also find the hybridisation of central atom and bond angles in the structures

#### 11th Standard CBSE Chemistry - Classification of Elements and Periodicity in Properties Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Use the periodic table to answer the following questions.
Identify an element with five electrons in the outer subshell.

• 2)

Which elements have the following electronic configuration? (Use only the periodic table.)
1s2, 2s2, 2p5

• 3)

Which elements have the following electronic configuration? (Use only the periodic table.)
[Xe] 6s2

• 4)

Which elements have the following electronic configuration? (Use only the periodic table.)
[Ar] 4s1, 3d10 (exception to rules)

• 5)

In p-block elements form acidic, basic and amphoteric oxides. Explain each property by giving two examples and also write the reactions of these oxides with water.

#### 11th CBSE Chemistry - Structure of Atom Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de-Broglie wavelength associated with the electron revolving around the orbit.

• 2)

Calculate the energy required for the process
$He^{ + }\left( g \right) \longrightarrow { He }^{ 2+ }\left( g \right) +{ e }^{ - }$
The ionisation energy for the atom in the ground state is $2.18\times { 10 }^{ -18 }J{ \quad atom }^{ -1 }$.

• 3)

A photon of wavelength 4 x 10-7 m strikes on the metal surface, the work function of the metal being 2.13 eV. Calculate the velocity of the photoelectron (1 eV = 1.6020 x 10-19 J).

• 4)

A beam of helium of atoms move with a velocity of $2.0\times { 10 }^{ 3 }{ ms }^{ -1 }$ Find the wavelength of the particle constituting the beam. (h = 6.626 $\times$10-34 Js).

• 5)

List the quantum number (ml and l) of electrons for 3d - orbital.
Notes:
l has the value 0 to (n - 1)
m has the value -l to l
The value of l never be equal to n or greater than it.

#### 11th CBSE Chemistry - Some Basic Concept of Chemistry Five Mark Question Paper - by Amit Pandya - Varanasi - View & Read

• 1)

How many atoms of He are present in 52 $\mu$ of He?

• 2)

A lady purchases a ring from a jeweller with diamonds embedded into it. The jeweller tells that total diamond used in the ring is five carat. How much weight he should subtract from the weight of the ring to get the weight of gold?

• 3)

Round up the following up to three significant figures.
34.216

• 4)

Copper sulphate crystals contain 25.45% Cu and 36.07% H2O. If the law of constant proportions is true then calculate the weight of Cu requires to obtain 40g of crystalline CuSo4.

• 5)

(i) A sample of drinking water was found to be severely contaminated with chloroform CHCL3 which is Carcinogenic in nature. The level of contamination was 15ppm (by mass).
(b) Determine the molarity of chloroform in the water in which the mole fraction of ethanol is 0.040

#### CBSE 11th Chemistry - State of Matter Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A gas is enclosed in the room. The temperature, pressure, density, and the number of moles respectively are t $^{o}$C, p atm, g cm-3 and n moles. What will be the values of pressure, temperature, density, and the number of moles in each compartment if the walls between the two compartments (say 1 and 2) are removed?

• 2)

A 2 L flask contains 1.6g of methane and 0.5 g of hydrogen at 27oC. Calculate the partial pressure of each gas in the mixture and also calculate the total pressure.

• 3)

0.64 g of an oxide of sulphur occupies 0.224 L at 2 bars and 273oC. Identify the compound.Also, find out the mass of one molecular of the gas.

• 4)

Why is the effect of temperature more important for the liquefaction of gases? Define critical temperature and critical pressure.

• 5)

The compression factor(compressibility factor) for one mole of a van der Waals gas at 0oC and 100 atm pressure is found to be 0.5. Assuming that the volume of a gas molecule is negligible, calculate the van der Walas' constant a.

#### 11th Standard CBSE Chemistry - Chemical Bonding and Molecular Structure Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Explain the following on the basis of valence bond theory. CCl4 and SiCl4 are tetrahedral.

• 2)

Explain the following on the basis of valence bond theory. The HSH bond angle is H2S is closer to 900 than HOH bond angle in H2O.

• 3)

Apart from tetrahedral geometry, another possible geometry for CH4 is square planar with the four H-atoms at the corners of the square and the C-atom t its centre. Ecplain, why CH4 is not square planar?

• 4)

On the basis of molecular orbital theory what is similarly between ${ F }_{ 2 },{ O }_{ 2 }^{ 2- }$

• 5)

On the basis of molecular orbital theory what is similarly between $CO,{ N }_{ 2 },{ NO }^{ + }$

#### 11th Standard CBSE Chemistry Unit 3 Classification of Elements and Periodicity in Properties Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Give the name and atomic number of the inert gas atom in which the total number of numbers of d-electrons is equal to the difference in numbers of total p and s electrons.

• 2)

Can an element with atomic number 126, if discovered, be accommodated in the present set up of the long form of periodic table?

• 3)

First member of each group of representative elements  ( i.e. sand p-block elements ) shows anomalous behaviour. Illustrate with two examples.

• 4)

Arrange the following as stated. 'Decreasing order of electropositive character of Cu, Fe Mg'

• 5)

Define (i) a group and (ii) a period, of the periodic table. How many periods and groups are there in the long form of the periodic table?

#### 11th Standard CBSE Chemistry Unit 2 Structure of Atom Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which of the following are isoelectronic species, i.e those having the same number of electrons?
Na+,K+,Mg2+,Ca2+,S2-,Ar

• 2)

Write the complete symbol for the atom with the given number (Z) and atomic mass (A). Z = 17, A  = 35

• 3)

Correct the following electronics configuration of the elements in the ground state.
${ 1s }^{ 2 }2s^{ 2 },{ 2p }^{ 6 },3s^{ 2 },{ 3p }^{ 6 },3d^{ 5 }$

• 4)

Correct the following electronics configuration of the elements in the ground state.
${ 1s }^{ 2 }2s^{ 2 },{ 2p }^{ 6 },3s^{ 2 },{ 3p }^{ 6 },3d^{ 4 },4s^{ 2 }$

• 5)

Which of the following sets of orbitals are degenerate and why? 2px, 2py and 2pz in C-atom.

#### 11th Standard CBSE Chemistry - Some Basic Concept of Chemistry Three Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How many amny significant figures present in the following? "5005"

• 2)

How many amny significant figures present in the following? "126000"

• 3)

To account for the atomic mass of nitrogen as 14.0067,$\mu$ what should be the ratio of and atoms ${ 15 }_{ N }$${ 14 }_{ N }$ in natural nitrogen? (atomic mass of ${ 14 }_{ N }$ = 14.00307 $\mu$ and ${ 15 }_{ N }$ = 15.001$\mu$)

• 4)

A compound contains 4.07% hydrogen, 24.27% carbon and 71.65 % chlorine. Its molar mass is 98.96 g. Determine its empirical and molecular formulae.

• 5)

Convert the following into meter. '40 Em (thickness of milky way galaxy)'

#### CBSE 11th Chemistry - Environmental Chemistry Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What could be the harmful effects of improper management of industrial and domestic solid waste in a city?

• 2)

For dry cleaning in the place of tetrachloroethene, liquefied carbon dioxide with suitable detergent is an alternative solvent. What type of harm to the environment will be prevented by stopping use of tetrachloroethene? Will use of liquefied carbon dioxide with detergent be completely safe from the point of view of pollution. Explain.

• 3)

What do you mean by primary and secondary pollutants of the air?

• 4)

Which zone is known as ozonosphere?

• 5)

Which main gases is responsible for damage in ozone layer?

#### 11th Standard CBSE Chemistry - Hydrocarbons Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Rotation around carbon-carbon single bond of ethane is not completely free. Justify the statement.

• 2)

On converting benzene to toluene, state whether there will be a rise or fall in the melting point.

• 3)

Why do you alkenes prefer to undergo electrophilic addition reaction while arenes prefer electrophilic substitution reactions? Explain

• 4)

Draw the cis- and trans-structures for hex-2-ene. Which iosmer will have higher b.p. and why?

• 5)

What effect does branching of an alkane chain has on its boiling point?

#### 11th Standard CBSE Chemistry - Organic Chemistry: Some Basic Principles and Techniques Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Give the common name of methanol.

• 2)

How many $\sigma$ and  $\pi$ bonds are present in each of the following molecules?
(ii) $CH_{ 3 }-CH=CH-CH_{ 2 }-C\equiv CH$

• 3)

Identify the most stable species in the following set of ions giving reasons
$\overset { - }{ C } { H }_{ 3 },\overset { - }{ C } { H }_{ 2 }CI,\overset { - }{ C } { H }CI_{ 2 },\overset { - }{ C } CI_{ 3 }$

• 4)

Which bond is more polar in the following pair of molecules?
H3C - H or H3C - Br

• 5)

What is meant by delocalization?

#### 11th Standard CBSE Chemistry - The p-block Elements Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Discuss the pattern of variation in the oxidation states of B to TI

• 2)

How does electron deficient compound BF3 achieve electronic saturation , i.e fully ooccupied outer electron shells?

• 3)

Give one chemical reaction to show that
Tin(II) chloride is a reducing agent.

• 4)

Give reasons.
Conc.HNO3 can be transported in aluminium container.

• 5)

Why does lime water turn milky when CO2  is passed through it.

#### CBSE 11th Chemistry - The s-Block Elements Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A white solid X is a compound of alkali metal. A piece of red litmus paper turns white when it is dipped into a freshly made aqueous solution of the white solid. Identify the white solid X.

• 2)

Write the Lewis structure of O2- ion and find out oxidation state of each oxygen atom ? What is the average oxidation state of oxygen in this ion ?

• 3)

Explain why can alkali and alkaline earth metals not be obtained by chemical reduction methods?

• 4)

What happens when magnesium reacts with SOgas ?

• 5)

When alkali metals dissolves in liquid ammonia, the solution can acquire different colours.Explain the reason for. this type of colour change

#### CBSE 11th Chemistry - Hydrogen Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

${ H }_{ 2 }{ O }_{ 2 }$ is a better oxidising agent than water as discussed below.Explain.

• 2)

Calculate the strength of 10 volume solution of hydrogen peroxide.

• 3)

Explain the correct context in which the following terms are used diprotium

• 4)

Would you expect the hydrides of N, O and F to have lower boiling points than the hydrides of their subsequent group members? Give reasons.

• 5)

How do you expect the metallic hydrides to be useful for hydrogen storage? Explain

#### 11th Standard CBSE Chemistry - Redox Reactions Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Balance the following equations in basic medium by ion electron and oxidation number methods and identify the oxidising agent and the reducing agent
$CI_{ 2 }O_{ 7 }(g)+H_{ 2 }O_{ 2 }(aq)\longrightarrow CIO_{ 2 }^{ - }(aq)+O_{ 2 }(g)$

• 2)

A solution of silver nitrate was stirred with iron rod.Will it cause any change in the concentration of silver and nitrate ions?

• 3)

How many millimoles of potassium dichromate is required to oxidise 24mL of 0.5 M Mohr's salt solution in acidic medium?

• 4)

Two half cells are AI3+ (aq) /AI and Mg2+ (aq)/Mg.The reduction potentials of these half-cells are -1.66 V and -2.36 V respectively. Calculate the cell potential. Write the cell reaction also.

• 5)

Assign oxidation number to the underlined elements in each of the following species - K2MnO4

#### 11th Standard CBSE Chemistry - Equilibrium Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

How much volume of 0.1 M HAc should be added to 50 mL of 0.2 M HAc solution if we want to prepare a buffer solution of pH 4.91. Given pKa for acetic acid is 4.76.

• 2)

Which of the following reactions involve homogeneous equilibrium and which involve heterogeneous equilibrium?
${ Ag }_{ 2 }O(s)+2HN{ O }_{ 3 }(aq)\rightleftharpoons 2{ Ag }NO_{ 3 }(aq)+{ H }_{ 2 }O(l)$

• 3)

Which of the following reactions involve homogeneous equilibrium and which involve heterogeneous equilibrium?
$2SO_{ 2 }(g)+O_{ 2 }(g)\rightleftharpoons 2SO_{ 3 }(g)$

• 4)

Explain why pure liquids and solids can be ignored while writing the value of equilibrium constants.

• 5)

The ester, ethyl acetate is formed by the reaction of ethanol and acetic acid and the equilibrium is represented as;
CH3COOH(l) + C2H5OH(l) ⇌ CH3COOC2H5(l) + H2 O(l)
Write the concentration ratio (concentration quotient) Q for this reaction. Note that water is not in excess and is not a solvent in this reaction.

#### CBSE 11th Chemistry - Thermodynamics Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The enthalpy of a vaporisation of CCI4 is 30.5 kJ mol-1. Calculate the heat required for the vaporisation of 284g of CCI4 at constant pressure (molar mass of CCI4 =154 g mol-1)

• 2)

Calculate the number of kJ of haet necessary to raise the temperature of 60.0g of aluminium from 35 $^{ \circ }$C to 55$^{ \circ }$C. Molar heat capacity of Al is 24Jmol$^{ -1 }$K$^{ -1 }$ . Molar mass of Al = 27gmol$^{ -1 }$

• 3)

18.0 g water completely vaporises at 100 oC and 1 bar pressure and the enthalpy change in the process is 40.79 KJ mol-1. What  will be the enthalpy change for vaporising two moles of water under the same conditions? What is the standard enthalpy of vaporisation for water?

• 4)

Although heat is path function but heats absorbed by the system under certain specific conditions is independent of path. what are those conditions? Explain when pressure remains constant.

• 5)

Derive the relationship of work for isothermal and free expansion of an ideal gas.

#### CBSE 11th Chemistry - State of Matter Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Use the information and data given below to answer the question, stronger intermolecular forces result in higher boiling point.
Strength of London forces increases with the number of electrons in the molecules. Boiling point of HF, HCI, HBr, and HI are 293 K, 189 K, 206 K and 238 K respectively.
Looking at the trend of boiling points of HCI, HBr, and HI, explain out of dipole-dipole interaction and London interaction, which one is predominant here.

• 2)

Calculate the kinetic energy of 2g of oxygen at -23oC

• 3)

The density of liquid CO2 at room temperature is 0.8 g cm-3 .how large a cartridge of liquid CO2 must be provided to inflate a life jacket of 4 L capacity at STP?

• 4)

It is desired to increase the volume of 800 mL of a gas by 20% keeping the pressure constant. To what temperature the gas must be heated if the initial temperature is 22oC?

• 5)

150 mL of a gas at NTP were taken to 20oC and 0.96 bar pressure. What is the change in volume of the gas?

#### 11th CBSE Chemistry - Chemical Bonding and Molecular Structure Two Mark Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O , N2, SO2 and ClF3 .

• 2)

Arrange the following bonds in order of increasing ionic character giving reason. N-H, F-H, C-H and O-H

• 3)

Give correct reasons for the following
BF3 has a zero dipole moment although the B-F bonds are polar.

• 4)

Arrange the following in order of decreasing bond angle, giving reason NO2$NO_{ 2 }^{ + }$ and $NO_{ 2 }^{ - }$

• 5)

Explain the shape of BrF5

#### CBSE 11th Chemistry Unit 3 Classification of Elements and Periodicity in Properties Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that?

• 2)

All transition elements are d-block elements, but all d-block elements are not transition elements. Explain.

• 3)

List the factors that can influence the ionic radius of an element.

• 4)

Show by a chemical reaction with water that ${ Na }_{ 2 }O$ is a basic oxide and $Cl_{ 2 }O_{ 7 }$is an acidic oxide.

• 5)

What is the periodic law given by Mendeleev? Is this periodic law the same as was observed by Lothar Meyer?

#### CBSE 11th Chemistry - Structure of Atom Two Marks Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Why does the charge to mass ratio of positive rays depend on the residual gas in the discharge tube? Why is the charge to mass ratio of all cathode rays are same?

• 2)

Calculate energy of one mole photons of radiation whose frequency is 5 x 1014 HZ.

• 3)

In astronomical observations, signals observed from the distant stars are generlly weak. If the photon detector receives a total of 3.15 x 10-18 J from the radiations of 600 nm, calculate the number of photons received by the detector.

• 4)

Calculate wave number of the line having frequency 5 x 1016 Hz.

• 5)

Calculate the energy of one mole of the photons of a beam of light having wavelength 25.0 $\mu$m.

#### 11th Standard CBSE Chemistry Unit 1 Some Basic Concept of Chemistry Two Mark Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Express the following number to three significant figures. "Sixty thousand"

• 2)

Express the following number to three significant figures. " 2.861$\times$10"

• 3)

The reactant which is entirely consumed in reaction is known as limiting reagent. In the reaction 2A + 4B $\Rightarrow$ 3C + 4D, when 5 moles of A react with 6 moles of B, then calculate the amount of C formed?

• 4)

The water level in a metric measuring cup is 0.75 L before the addition of a pebble weighing 150 g. The water level after submerging the pebble is 0.82 L. Determine the density of the pebble.

• 5)

One of the statements of Dalton's atomic theory is given below "compounds are formed when atoms of different elements combine in a fixed ratio". Which laws of chemical combination is not related to this statement?

#### CBSE 11th Chemistry Unit 14 Environmental Chemistry Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Why does water covered with excessive algae growth become polluted?

• 2)

In what regions of the atmosphere,the temperature increases with altitude and in which regions it decreases?

• 3)

Name three natural sources of air pollution.

• 4)

What are viable and non-viable particulates?

• 5)

What is the nature of 'London smog' and why?

#### CBSE 11th Chemistry Unit 13 Hydrocarbons Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What happen when iodoethane is reduced with hydroiodic acid and red phosphorus?

• 2)

What is difference between alkylation and acylation?

• 3)

Which of the following exhibit geometrical isomerism?
But-2-ene

• 4)

What happens when iso-butene is treated with hot alkaline KMnO4 ?

• 5)

Why is it possible to have pure staggered ethane or pure eclipsed ethane?

#### CBSE 11th Chemistry Unit 12 Organic Chemistry: Some Basic Principles and Techniques Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

In the organic compound CH2=CH-CH2-CH2-C$\equiv$CH, the CH-CH2 bond is formed by the interaction of a pair of hybridised orbitals:

• 2)

The following reaction is classified as:
CH3CH2I + KOH (aq) $\rightarrow$CH3CH2OH + KI

• 3)

What are primary and secondary suffixes as applied to IUPAC nomenclature?

• 4)

How many $\sigma$ and    $\pi$ bonds are present in each of the following molecules
(ii) $CH_{ 2 }==C==CHCH_{ 3 }$

• 5)

Explain the term metamerism.

#### CBSE 11th Chemistry Unit 11 The p-block Elements Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What property of anhydrous AlCl3 makes it a very good preparative reagent in organic chemistry?

• 2)

What is the formula of kernite, an ore of boron?

• 3)

Define photosynthesis. In what way it is helpful for us?

• 4)

Are all the B-H bonds in diborane equivalent?

• 5)

Carbon dioxide is passed through a suspension of powdered limestone is water.Write balanced chemical equation for the above reaction.

#### CBSE 11th Chemistry - The s-Block Elements Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which of the alkali metal is having least melting point?

• 2)

Which one of the following alkali metals give hydrated salts?

• 3)

Which one of the following alkaline earth metal carbonates is thermally most stable

• 4)

State as to why a solution of Na2CO3 is alkaline?

• 5)

The second ionisation enthalpy of calcium is more that of first and yet calcium forms MgCI2 not MgCL. why?

#### CBSE 11th Chemistry - Hydrogen Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Suggest a method to show the electronegative nature of hydrogen.

• 2)

How can saline hydrides remove traces of water from organic compounds?

• 3)

Explain why beryllium forms a covalent hydride while calcium forms an iconic hydride.

• 4)

Name the isotope of hydrogen which is commonly used as a tracer in organic reactions.

• 5)

Name the constituents of water gas.

#### 11th Standard CBSE Chemistry Unit 8 Redox Reactions Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What is meant by oxidation number of an element?

• 2)

Is the reaction, $N{ H }_{ 3 }+HCl\longrightarrow { NH }_{ 4 }^{ + }+Cl^{ - },$ an oxidation-reduction reaction?Explain your answer

• 3)

At what concentration of Cu2+ (aq), will the electrode potential become equal to its standard electrode potential?

• 4)

Does the oxidation number of an element in any molecule or any polyatomic ion represent the actual charge on it?

• 5)

The compound YBa2Cu3O7, Which shows superconductivity, has copper in x oxidation state. Assume that the rare earth element yttrium is in its usual +3 oxidation state. Predict the value of x.

#### 11th Standard CBSE Chemistry Unit 7 Equilibrium Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A tank is full of water. Water is coming in as well as going out at same rate. What will happen to level of water in a tank? What is name given to such a state?

• 2)

Why cannot KCl undergo hydrolysis?

• 3)

What is the expression for ${ k }_{ sp } \ of \ { Ag }_{ 2 }Cr{ 0 }_{ 4 }?$

• 4)

Under the conditions is a substance precipitated from its solution?

• 5)

pKa  value of acids A,B,C,D are 1.5, 3.5, 2.0 and 5.0.Which of them is strongest acid?

#### 11th Standard CBSE Chemistry Unit 6 Thermodynamics Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A thermodynamic state function is a quantity

• 2)

A reaction, A + B $\rightarrow$  C + D + q is found to have a positive entropy change. The reaction will be

• 3)

As per the available data:

• 4)

In the equation, ${ N }_{ 2 }(g)+3{ H }_{ 2 }(g)\rightleftharpoons 2N{ H }_{ 3 }(g)$ what would be the sign of work done?

• 5)

At 1 atm will the ${ \triangle }_{ f }{ H }^{ \circ }$ be zero for Cl2(g) and Br2 (g)? Explain.

#### 11th Standard CBSE Chemistry Unit 5 State of Matter Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

One of the assumptions of kinetic theory of gases states that "there is no force of attraction between the molecules of a gas "How far is this statement correct?Is it possible to liquefy an ideal gas? Explain.

• 2)

A gas that follows Boyle's law, Charle's law and Avogadro's law is called an ideal gas.Under what condition a real gas would behave ideally?

• 3)

Explain why temperature of a boiling liquid remains constant?

• 4)

Explain the physical significance of van derWaals' parameters.

• 5)

What would have happened to the gas if the molecular collision were not elastic?

#### 11th Standard CBSE Chemistry Unit 4 Chemical Bonding and Molecular Structure Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Why axial bonds of PCI5 are longer than equatorial bonds?

• 2)

Draw the Lewis dot structure of ${ O }_{ 2 }^{ 2- }$

• 3)

How is the bond angle affected by the presence of long pairs?

• 4)

The following combinations of atomic orbitals will give antibonding $\pi$- molecular orbital (assume Z-axis as an internuclear axis.): '2s+2pz'

• 5)

Which of two: KCl or Cl2 has higher boiling point and why?

#### 11th Standard CBSE Chemistry Unit 3 Classification of Elements and Periodicity in Properties Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Why were the names eka-aluminium and eka-silicon given to gallium and germanium by Mendeleev?

• 2)

Why do elements in the same group have similar physical and chemical properties?

• 3)

A boy has reported the radii of Cu,Cu+ and Cu2+ as 0.096 nm,0.122 nm and 0.072 nm respectively.However, it has been noticed that he interchanged the values by mistake. Assign the correct values to different species.

• 4)

Four elements have the following first ionisation enthalpies ( in kJ mol-1); 869, 941, 1191 and 1142. The elements, in random order, are Se, Br, Te and I. Which element has an ionisation enthalphy of 869 kJ mol-1 and 1142 kJmol-1 respectively?

• 5)

Explain why chlorine can be converted into chloride ion more easily as compared to fluoride ion from fluorine.

#### 11th Standard CBSE Chemistry Unit 2 Structure of Atom Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

What is the experimental evidence in support of the idea that electronic energies in an atom are quantised?

• 2)

Which two discoveries put strong challenge to the Bohr model?

• 3)

The magnitude of charge on the electron is $4.8\times { 10 }^{ -10 }$ esu. What is the charge on the nucleus of a helium atom?

• 4)

What physical meaning is attributed to the square of the absolute value of wave function $|\psi |^{ 2 }$?

• 5)

An electron is in one of the 3d-orbitals .give the possible values of n, l, and m for this electron.

#### 11th Standard CBSE Chemistry Unit 1 Some Basic Concept of Chemistry Book Back Questions - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The empirical formula of sucrose is

• 2)

The number of significant figures in 0.0101 is

• 3)

The number of grams of oxygen in 0.10 mol of Na2CO3· 10H2O is

• 4)

The mass of an atom of nitrogen is

• 5)

Using the unit conversion factor, express 1.54mm s-1 into pm $\mu$s-1 .

#### 11th Standard CBSE Chemistry Unit 9 Hydrogen One Mark Question and Answer - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Hydrogen gas is generally prepared by the

• 2)

Hydrogen peroxide is used as

• 3)

Water may be softened using

• 4)

On treatment of hard water with zeolite, sodium ions get exchanged with

• 5)

Calgon, which is used as a water softener, has the formula

#### 11th Standard CBSE Chemistry Unit 8 Redox Reactions One Mark Question and Answer - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Among the following molecules, in which does bromine show the maximum oxidation number?

• 2)

Which of the following halogens do not exhibit a positive oxidation number in their compounds?

• 3)

Which of the following is most powerful oxidizing agent in the following

• 4)

On the reaction 2Ag + 2H2SO4 $\rightarrow$ Ag2So4 + 2H2O+SO2  sulphuric acid acts as

• 5)

The oxidation number of the carboxylic carbon atom in CHCOOH is

#### 11th Standard CBSE Chemistry Unit 7 Equilibrium One Mark Question and Answer - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The equilibrium expression, Kc= [CO2] represents the reaction.

• 2)

Hydrogen molecule (H2) can be dissociated into hydrogen atoms (H). Which one of the following changes will not increase the number of atoms present at equilibrium?

• 3)

What is the expression for Keq for the reaction
2N2O (g) + O2 (g) ⇌ 4NO (g)?

• 4)

A catalyst will increase the rate of a chemical reaction by

• 5)

What is the correct expression for the representation of the solubility product constant
of Ag2 CrO4 ?

#### 11th Standard CBSE Chemistry Unit 6 Thermodynamics One Mark Question with Answer - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A thermodynamic state function is a quantity

• 2)

For the process to occur under adiabatic conditions, the correct condition is:

• 3)

As per the available data:

• 4)

Thermodynamics is applicable to

• 5)

An isochoric process takes place at constant

#### 11th Standard CBSE Chemistry Unit 5 State of Matter One Mark Question with Answer Key - by Ashutosh Saran - Gurgaon - View & Read

• 1)

For one mole of a gas, the ideal gas equation is

• 2)

The cleansing action of soaps and detergents is due to

• 3)

In van der Waals equation of state for a non-ideal gas the net force of attaction among the molecules is given by

• 4)

The compressibility factor, z for an ideal gas is

• 5)

Which of the following gases will have the lowest rate of diffusion?

#### 11th Standard CBSE Chemistry Unit 4 Chemical Bonding and Molecular Structure One Mark Question and Answer - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A co-ordinate bond is formed by

• 2)

The species CO, CN- and N2 are

• 3)

The axial overlap between the two orbitals leads to the formation of a:

• 4)

In SO2 molecule, S atom is:

• 5)

A molecule or ion is stable if:

#### 11th CBSE Chemistry Unit 3 Classification of Elements and Periodicity in Properties One Mark Question with Answer Key - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The highest ionization energy is exhibited by

• 2)

Which of the following oxides is neutral?

• 3)

Which of the following is arranged in order of increasing radius?

• 4)

What is the electronic configuration of the elements of group 14?

• 5)

Among the following elements, which has the least electron affinity?

#### 11th CBSE Chemistry Unit 2 Structure of Atom One Mark Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Cathode rays are deflected by

• 2)

The Balmer series in the spectrum of hydrogen atom falls in

• 3)

The energy needed to remove a single electron (most loosely bound) from an isolated gaseous atom is called

• 4)

The maximum number of electrons in a sub-shell is given by the equation

• 5)

If the value of azimuthal quantum number is 2, what will be the values for magnetic quantum number?

#### 11th CBSE Unit 1 Some Basic Concept of Chemistry One Mark Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

One mole of CO2 contains

• 2)

5.6 litres of oxygen at NTP is equivalent to

• 3)

Which of the following has the highest mass?

• 4)

The number of significant figures in 0.0101 is

• 5)

The number of grams of oxygen in 0.10 mol of Na2CO3· 10H2O is

#### 11th CBSE Chemistry The p-block Elements Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which of the following compound is an important catalyst as well as a Lewis acid?

• 2)

Silicon carbide (SiC) is known as

• 3)

Which of the following is a purely acidic oxide?

• 4)

Which of the following molecules have zero dipole moment?

• 5)

Silicon shows a diagonal relation with

#### 11th CBSE Chemistry The s-Block Elements Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Which one of the following alkali metals give hydrated salts?

• 2)

The reducing property of alkali metals follows the order

• 3)

Lithium shows a diagonal relationship with

• 4)

The oxide of which of the following metals is amphoteric?

• 5)

Hydrides as well as halides of alkaline earth metals tend to polymerize

#### 11th CBSE Chemistry Hydrogen Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

Hydrogen gas is generally prepared by the

• 2)

On treatment of hard water with zeolite, sodium ions get exchanged with

• 3)

The higher density of water than that of ice is due to

• 4)

Zeolite is

• 5)

The decomposition of H2O2 is retarded by

#### 11th Standard CBSE Chemistry Redox Reactions Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

On the reaction 2Ag + 2H2SO4 $\rightarrow$ Ag2So4 + 2H2O+SO2  sulphuric acid acts as

• 2)

When methane is burnt in oxygen to produce CO2 and H20 the oxidation number of carbon changes by

• 3)

Which of the following are not redox reactions?

• 4)

Which one among the following is not example of autoredox reaction?

• 5)

In the ethylene molecule the two carbon atoms have the oxidation numbers.

#### 11th Standard CBSE Chemistry Unit 7 Equilibrium Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The equilibrium expression, Kc= [CO2] represents the reaction.

• 2)

In a closed system
A(S) ⇌ 4 B(g) + 3 C(g)
If partial pressure of C is doubled, then partial pressure of B will be

• 3)

What effect does a catalyst have on the equilibrium position of a reaction?

• 4)

A chemist dissolves an excess of BaSO4 in pure water at 25°C if its Ksp = 1 x 10-10 what is the concentration of barium in the water?

• 5)

If in a mixture where Q = k is combined, then what happens?

#### 11th CBSE Chemistry Unit 6 Thermodynamics Model Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A thermodynamic state function is a quantity

• 2)

A reaction, A + B $\rightarrow$  C + D + q is found to have a positive entropy change. The reaction will be

• 3)

As per the available data:

• 4)

Thermodynamics is applicable to

• 5)

An isochoric process takes place at constant

#### 11th CBSE Chemistry Unit 5 State of Matter Important Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

For one mole of a gas, the ideal gas equation is

• 2)

Viscosity of a liquid is a measure of

• 3)

The cleansing action of soaps and detergents is due to

• 4)

The compressibility factor, z for an ideal gas is

• 5)

Which of the following gases will have the lowest rate of diffusion?

#### 11th Standard CBSE Chemistry Unit 4 Chemical Bonding and Molecular Structure Important Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

A co-ordinate bond is formed by

• 2)

The species CO, CN- and N2 are

• 3)

The molecule Ne2 does not exist because

• 4)

Which one is diamagnetic among NO, NO and NO-?

• 5)

sp3, sp2 and sp hybridized carbon atom, the p character is maximum in:

#### 11th Standard CBSE Chemistry Unit 3 Classification of Elements and Periodicity in Properties Important Question Paper - by Ashutosh Saran - Gurgaon - View & Read

• 1)

The highest ionization energy is exhibited by

• 2)

Which of the following oxides is neutral?

• 3)

Which of the following is arranged in order of increasing radius?

• 4)

What is the electronic configuration of the elements of group 14?

• 5)

Among the following elements, which has the least electron affinity?

### CBSE Education Study Materials

#### 11th CBSE Chemistry 2019 - 2020 Academic Syllabus - by Ashutosh Saran - Gurgaon Aug 21, 2019 Aug 21, 2019

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