Calculate the moles of hydrogen (H₂) present in a 500 mL sample of hydrogen gas at a pressure of 1 bar and 27^oC.

Calculate dissociation of conjugate base of HF, K_a = 6.8 x 10 ^-4

Assign oxidation number to the underlined elements in each of the following species -NaBH4

Which bond is more polar in the following pairs of molecules:
(a) H₃C - H or H₃C - Br
(b) H₃C - NH₂ or H₃C - OH
(c) H₃C - OH or H₃C - SH

Classify as covalent, ionic or polymeric interstitial hydrides
BeH ₂

What are particulates?What are their sources?

For a hypothetical process, A\(\longrightarrow \) B, predict whether the process is spontaneous or not when 
\(\triangle \)H is +ve, T\(\triangle \)S is +ve and T\(\triangle \)S is greater than \(\triangle \)H.

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

The Balmer series of spectral lines for hydrogen appear in the visible region. What is the lower energy level that these electronic transitions starts from, and what transitions correspond to the spectral lines at 379.0 nm and 430.0 nm, respectively?

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

What type of curves are obtained when at constant temperature, we plot
p V vs p

Write chemical reactions to justify that hydrogen peroxide can function as an oxidising as well as reducing agent.

One day Rohan and Amit were discussing that vechicles on roads are increasing day-by-day.Emission levels of gases are very high which are leading to respiratory diseases.CNG and LPG are being used instead of diesel.So they decided to go to office through one car and use of CNG for driving the car instead of diesel.
(ii)Diesel vechicles should be taxed to more extent.Do you agree?Give reason.

Calculate the numberof choride ions in 500 mL of 0.05 M AlCl₃ solution.

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 What is soft water?

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

Give the composition and uses of the following alloys.
Magnalium

A sample of 0.50 g of an organic compound was treated according to Kjeldahl’s method. The ammonia evolved was absorbed in 50 ml of 0.5 M H₂SO₄. The residual acid required 60 mL of 0.5 M solution of NaOH for neutralisation. Find the percentage composition of nitrogen in the compound.

The sums of first and second ionization energies and those of third and fourth ionization energies, (in M J mol^-1) of nickel and platinum are

Based on this information, write
(i) the most common oxidation states of Ni and Pt.
(ii) name of metal (Ni or Pt) which can easily form compounds in its +4 oxidation state.

CIF₃ exists but FCl₃ does not. Give reason.

What is common ion effect? Give the application of buffer in daily life.

How will you distinguish between Na₂CO₃ and NaHCO₃

In what ways lithium shows similarities to magnesium in its chemical behaviour?

Balance the following equation by the oxidation number method.
\({ I }_{ 2 }+{ NO }_{ 3 }^{ - }\longrightarrow { NO }_{ 2 }+{ IO }_{ 3 }^{ - }\)

An element X forms four oside having percentages of X equal to 77.4%,63.2%,69.9% and 72.0%. Verify law of multiple propotions.

Calculate the total presure in a mixture of 4 g of  0₂ and 2 g of H₂ confined to a total volume of 1 L at 0^oC (R = 0.0821 L atm mol^-1).

Name the elements of group 14. Discuss the variation in characteristics of the group with reference to
i)oxidation state

Discuss the principle of estimation of halogens, sulphur and phosphorus present in an organic compound.

What were the weaknesses or limitations of Bohr's model of atoms? Briefly describe the quantum mechanical model of atom.

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).