#### Important One Mark Question Paper

11th Standard

Reg.No. :
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Chemistry

Time : 01:00:00 Hrs
Total Marks : 50

50 x 1 = 50
1. 40 ml of methane is completely burnt using 80 ml of oxygen at room temperature The volume of gas left after cooling to room temperature is _______.

(a)

40 ml CO2 gas

(b)

40 ml CO2 gas and 80 ml H2O gas

(c)

60 ml CO2 gas and 60 ml H2O gas

(d)

120 ml CO2 gas

2. The number of water molecules in a drop of water weighing 0.018 g is ________.

(a)

6.022$\times$1026

(b)

6.022$\times$1023

(c)

6.022$\times$1020

(d)

9.9 $\times$1022

3. Fe2 + $\longrightarrow$ Fe3+ + e- is a ________ reaction.

(a)

redox

(b)

reduction

(c)

oxidation

(d)

decomposition

4. The oxidation number of hydrogen in LiH is _________

(a)

+1

(b)

-1

(c)

+2

(d)

-2

5. Rusting of iron articles is an example of ___________ reaction

(a)

Combustion

(b)

decomposition

(c)

redox

(d)

hydrolysis

6. The correct increasing order of the oxidation state of sulphur in the anions ${ SO }_{ 3 }^{ 2- },{ SO }_{ 3 }^{ 2- }{ , }{ { S }_{ 2 }{ O } }_{ 4 }^{ 2- },{ S }_{ 2 }{ O }_{ 6 }^{ 2- }$ is _________.

(a)

${ SO }_{ 3 }^{ 2- }<{ SO }_{ 4 }^{ 2- }<{ { S }_{ 2 }{ O } }_{ 4 }^{ 2- }<{ S }_{ 2 }{ O }_{ 6 }^{ 2- }$

(b)

${ SO }_{ 4 }^{ 2- }<{ SO }_{ 4 }^{ 2- }<{ S }_{ 2 }{ O }_{ 6 }^{ 2- }<{ SO }_{ 3 }^{ 2- }$

(c)

${ { S }_{ 2 }{ O } }_{ 4 }^{ 2- }<{ SO }_{ 3 }^{ 2- }<{ S }_{ 2 }{ O }_{ 6 }^{ 2- }<{ SO }_{ 4 }^{ 2- }$

(d)

${ S }_{ 2 }{ O }_{ 6 }^{ 2- }<{ SO }_{ 4 }^{ 2- }<{ SO }_{ 4 }^{ 2- }<{ SO }_{ 3 }^{ 2- }$

7. Maximum oxidation state is present in the central metal atom of which compound

(a)

CrO2Cl2

(b)

MnO2

(c)

[Fe(CN)6]3-

(d)

MnO

8. Unit of Avogadro's number is _______________.

(a)

mol

(b)

g

(c)

mol -1

(d)

No unit

9. Equal volume of N2 and H2 react to form ammonia under suitable condition then the limiting reagent is ____________.

(a)

H2

(b)

N2

(c)

NH3

(d)

No Reactant is a limiting regent

10. A gas is found to have a formula (CO)x. If its vapour density is 70, the value of X is

(a)

2.3

(b)

3.0

(c)

5.0

(d)

6.0

11. If 30 ml of ${ H }_{ 2 }$  and 20 ml of ${ 0 }_{ 2 }$  reacts to form water.  what is left at the end of the reaction?

(a)

10mL of ${ H }_{ 2 }$

(b)

5 mL of ${ H }_{ 2 }$

(c)

10 mL of   ${ 0 }_{ 2 }$

(d)

5 mL of ${ 0 }_{ 2 }$

12. Which has maximum number of significant figures?

(a)

0.000010

(b)

0.216

(c)

2.1$\times$ 106

(d)

0.021

13. Which one of the following is the standard for atomic mass?

(a)

1H1

(b)

6C12

(c)

6C14

(d)

8O16

14. The oxidation number of fluorine in all its compounds is equal to ______________.

(a)

-1

(b)

+1

(c)

-2

(d)

+2

15. Based on equation E = $-2.178\times { 10 }^{ -18 }J\left( \frac { { Z }^{ 2 } }{ { n }^{ 2 } } \right)$certain conclusions are written. Which of them is not correct?

(a)

Equation can be used to calculate the change in energy when the electron changes orbit

(b)

For n = 1, the electron has a more negative energy than it does for n = 6 which means that the electron is more loosely bound in the smallest allowed orbit

(c)

The negative sign in equation simply means that the energy of electron bound to the nucleus is lower than it would be if the electrons were at the infinite distance from the nucleus.

(d)

Larger the value of n, the larger is the orbit radius.

16. In multi-electron atom,4s-orbital is lower in energy than __________

(a)

3d-orbital

(b)

3p-orbital

(c)

2s-orbital

(d)

2p-orbital

17. Which of the following configuration is correct for iron?

(a)

1s22s22p63s23p64s23d7

(b)

1s22s22p63s23p64s23d6

(c)

1s22s22p63s23p63d7

(d)

1s22s22p63s23p64s23d7

18. Bohr's equation for energy of an election in a hydrogen atom is given as______

(a)

$E=\frac { -1312 }{ { n }^{ 2 } } KJ{ mol }^{ -1 }$

(b)

$E=\frac { -1312 }{ { n }^{ 2 }{ h }^{ 2 } } KJ{ mol }^{ -1 }$

(c)

E = hv

(d)

$E=\frac { 4{ \pi }^{ 2 }{ me }^{ 4 } }{ { n }^{ 2 }{ h }^{ 2 } } KJ{ mol }^{ -1 }$

19. The quantum no. that is not related to an orbital is?

(a)

n

(b)

1

(c)

m

(d)

s

20. The region where the probability density function of electron reduces to zero is called__________.

(a)

orbit

(b)

orbital

(c)

nodal surface

(d)

subshell

21. The orbital with n = 3 and l = 2 is____.

(a)

3s

(b)

3p

(c)

3d

(d)

3j

22. The first list of 23 chemical elements was published by _____ in the year 1789.

(a)

Berzelius

(b)

Dobereiner

(c)

Lavoisier

(d)

John Dalton

23. Elements which generally exhibit multiple oxidation states and whose ions are usually coloured are ___________

(a)

metalliods

(b)

transition elements

(c)

non-metals

(d)

gases

24. The element with atomic number 31 belongs to _____

(a)

s-block

(b)

p-block

(c)

d-block

(d)

f-block

25. Which of the following statement is incorrect?

(a)

The ionization potential of nitrogen is greater than that of oxygen

(b)

The electron affinity of F is greater than that of Cl.

(c)

The ionization potential of Mg is greater than aluminium.

(d)

The electronegativity of F is greater than that of Cl.

26. Be resembles much with

(a)

Li

(b)

Al

(c)

Zn

(d)

Ra

27. For which of the following crystals would you expect the assumption of anion-anion contact to be valid?

(a)

CsBr

(b)

NaF

(c)

KCl

(d)

NaI

28. Which of the following has the highest ionisation enthalpy?

(a)

P

(b)

N

(c)

As

(d)

Sb

29. In the periodic table, with the increase in atomic number, the metallic character of an element

(a)

decrease in a period and increases in a group

(b)

increases in a period and decreases in a group

(c)

increases in a period as well as in the group

(d)

decreases in a period and also in the group

30. Consider the following statements
(i) In Chancourtois classification, elements differed from each other in atomic weight by 16 or multiples of 16 fell very nearly on the same vertical line.
(ii) Mendeleev's periodic law is based on atomic weight.
(iii) Mendeleev listed the 117 elements known at that time and are arranged in the order of atomic numbers.
Which of the following statement is/are not correct?

(a)

(i) only

(b)

(ii) and (iii)

(c)

(iii) only

(d)

(i),(ii) ,(iii)

31. The longest form of periodic table was constructed by______

(a)

Dmitri Mendeleev

(b)

Henry Moseley

(c)

Lothar Meyer

(d)

Newlands

32. Consider the isoelectronic species Na+, Mg2+, F- and O2-. The correct order of increasing length of their radius is ______________

(a)

F- < O2- < Mg2+< Na+

(b)

Mg2+ < Na+ < F- < O2-

(c)

O2- < F- < Na+ < Mg2+

(d)

O2- < F- < Mg2+ < Na+

33. When zeolite which is hydrated sodium aluminium silicate is treated with hard water, the sodium ions are exchanged with

(a)

$H^{+}$ ions

(b)

$Mg^{2}$ions

(c)

$Ca^{2+}$ ions

(d)

Both $Ca^{2+}$ and  $Mg^{2+}$

34. On heating which of the following releases CO2 most easily?

(a)

K2CO3

(b)

Na2CO3

(c)

MgCO3

(d)

CaCO3

35. Which of the following can oxidise Hydrogen peroxide?

(a)

acidified KMnO4

(b)

Cu

(c)

dil. HNO3

(d)

CrO2Cl2

36. Consider the following statements
1. Alkali metals are soft.
2. Alkali metals show high reactivity
3. I.E of alkali metal decreases down the group
Which of the following statement(s) given above is/ are correct?

(a)

1 & 3

(b)

only I

(c)

2 & 3

(d)

1, 2 & 3

37. Which of the following statements is true about Ca(OH)2?

(a)

It is used in the preparation of bleaching powder

(b)

It is a light blue solid

(c)

It is a light blue solid

(d)

It is used in the manufacture of cement

38. Molten sodium chloride conducts electricity due to the presence of

(a)

free electrons

(b)

ions

(c)

Na atom

(d)

CI atom

39. Which one of the following gives green spark in fire works?

(a)

Magnesium chloride

(b)

Sodium chloride

(c)

Barium bromide

(d)

Potassium iodide

40. At identical temperature and pressure, the rate of diffusion of hydrogen gas is 3$\sqrt { 3 }$ times that of a hydrocarbon having molecular formula CnH2n-2. What is the value of n ?

(a)

8

(b)

4

(c)

3

(d)

1

41. The rice is cooked earlier in pressure cooker because

(a)

boiling point increases with increasing pressure

(b)

boiling point decreases with increasing pressure

(c)

Internal energy is not lost while cooking in pressure cooker

(d)

Extra pressure of pressure cooker softens the rice

42. A gas at a pressure of 5.0 atm is heated from 0o to 546oC and simultaneously compressed to one - third of its original volume. Hence, final pressure is

(a)

10.0 atm

(b)

30.0 atm

(c)

45.0 atm

(d)

5.0 atm

43. Select the correct statement(s).

(a)

Absolute zero (0 K) os the temperature reached when all possible thermal energy has been removed from a substance.

(b)

A substance cannot be cooled any further after all thermal energy has been removed.

(c)

Both (a) and (b)

(d)

None of the above

44. At a high altitude water boils at 95oC instead of 100oC as at sea level because

(a)

the atmospheric pressure is greater

(b)

the atmospheric pressure is less

(c)

the climate is cooler

(d)

the vapour pressure of water is greater

45. The value of critical pressure of CO2 is ___________.

(a)

173 atm

(b)

73 atm

(c)

1 atm

(d)

22.4 atm

46. A gas undergoes A to B through three different processes 1, 2 and 3 as shown in the figure. The heat supplied to the gas is Q1, Q2 and Q3 respectively, then

(a)

Q= Q2 = Q3

(b)

Q1 < Q2 < Q3

(c)

Q1 > Q2 > Q3

(d)

Q1 = Q2 > Q3

47. In the cyclic process ABCDA shown in the figure, consider the following statements

I. Area ABCDA=Work done on the gas
II. Area ABCD=Net heat absorbed
III. Change in the internal energy in cycle=0
Which of these are correct?

(a)

I only

(b)

II only

(c)

II and III

(d)

I, II and III

48. The internal energy of a gas is given by U = 2pV. It expands from Vo to 2Vo against a constant pressure Po' The heat absorbed by the gas in the process is

(a)

2p0V0

(b)

4p0V0

(c)

3p0V0

(d)

p0V0

49. The increase in internal energy of 1kg of water at 100°C when it is converted into steam at the same temperature and at 1 atmospheric pressure will be

(a)

1.04 x 106J

(b)

2.08 x 106J

(c)

4.16 x 106J

(d)

8.32 x 106J

50. Mathematically, the third law of thermodynamics is expressed as _______

(a)

$\overset{\lim}{T\rightarrow 0}{ S=0 }$

(b)

$\overset{\lim}{T\rightarrow \infty} {S=1 }$.

(c)

ΔU = q + w

(d)

G = H - TS