Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Chemistry

Write the products formed when CH₃CHO reacts with the following reagents : H₂N – OH

Define the following term:

Anomers 

Distinguish between Hexagonal and monoclinic unit cells

Distinguish between Face-centred and end-centred unit cells.

Explain how much portion of an atom located at (i) corner and (ii) body-centre of a cubic unit cell is part of its neighbouring unit cell.

An element with molar mass 2.7 × 10^-2 kg mol^-1 forms a cubic unit cell with edge length 405 pm. If its density is 2.7 × 103 kg m⁻³, what is the nature of the cubic unit cell?

What is the coordination number of atoms in a cubic close-packed structure?

How can you determine the atomic mass of an unknown metal if you know its density and the dimension of its unit cell? Explain.

H₂S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in water at STP is 0.195 m, calculate Henry’s law constant.

Henry’s law constant for CO₂ in water is 1.67 × 10⁸ Pa at 298 K. Calculate the quantity of CO₂ in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.

The partial pressure of ethane over a solution containing 6.56 × 10⁻³ g of ethane is 1 bar. If the solution contains 5.00 × 10⁻² g of ethane, then what shall be the partial pressure of the gas?

Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain.

Cyclohexane, KCl, CH₃OH, CH₃CN

Henry’s law constant for the molality of methane in benzene at 298 K is 4.27 × 10⁵ mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.

The air is a mixture of a number of gases. The major components are oxygen and nitrogen with approximate proportion of 20% is to 79% by volume at 298 K. The water is in equilibrium with air at a pressure of 10 atm. At 298 K if the Henry’s law constants for oxygen and nitrogen are 3.30 × 10⁷ mm and 6.51 × 10⁷ mm respectively, calculate the composition of these gases in water.

Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.

Calculate the emf of the cell in which the following reaction takes place:

\[\ce{Ni_{(s)} + 2Ag+ (0.002 M) -> Ni^{2+} (0.160 M) + 2Ag_{(s)}}\]

Given that \[\ce{E^\circ_{cell}}\] = 1.05 V

A first order reaction has a rate constant 1.15 × 10⁻³ s⁻¹. How long will 5 g of this reactant take to reduce to 3 g?

Time required to decompose SO₂Cl₂ to half of its initial amount is 60 minutes. If the decomposition is a first order reaction, calculate the rate constant of the reaction.

The following data were obtained during the first order thermal decomposition of SO₂Cl₂ at a constant volume.

\[\ce{SO2Cl2_{(g)} -> SO2_{(g)} + Cl2_{(g)}}\]

In a pseudo first order reaction in water, the following results were obtained:

Calculate the average rate of reaction between the time interval 30 to 60 seconds.