List of top Chemistry Questions on Solutions asked in CBSE CLASS XII

Calculate the boiling point of a solution containing 0.61 g of benzoic acid (122 \( g mol^{-1} \)) in 5 g of \( CS_2 \) in which it dimerises to 88%. \( T_b^\circ(CS_2) = 46.2^\circ C, K_b = 2.3 K kg mol^{-1} \).

What type of deviation from Raoult’s law is shown by mixture of ethanol and acetone? Give reason. What will happen to the boiling point of the solution on mixing ethanol and acetone?

Assertion (A) : Components of azeotropes are easily separated by fractional distillation.
Reason (R) : Components of an azeotrope have same composition in liquid and vapour phase.

Which of the following solutions will have the highest osmotic pressure?

What type of azeotrope will be formed by a solution of benzene and chloroform? Give reason.

A solution is prepared by dissolving 0.088 g of potassium sulphate in 2 L of water at 27\(^\circ\)C. Assuming complete dissociation, determine its osmotic pressure. (Given: \(R = 0.082 \, L\,atm\,K^{-1}\,mol^{-1}\), Molar mass of K\(_2\)SO\(_4\) = 174 g mol\(^{-1}\))

Write two differences between ideal and non-ideal solutions.

Calculate the freezing point of a solution when \(10.5\) g of MgBr\(_2\) was dissolved in 250 g of water, assuming MgBr\(_2\) undergoes complete dissociation. (Given: Molar mass of MgBr\(_2\) = 184 g mol\(^{-1}\), \(K_f\) for water = 1.86 K kg mol\(^{-1}\))

State Henry’s law. Calculate the mole fraction of CO\(_2\) in water at 298 K under 700 mm Hg pressure. (Given: Henry’s constant for CO\(_2\) in water at 298 K = \( 1.25 \times 10^6 \) mm Hg)

1.00 molal aqueous solution of trichloroacetic acid is heated to its boiling point. The boiling point of this solution was found to be 100.18\(^\circ\)C. Calculate the Van’t Hoff factor for trichloroacetic acid. (Given: \( K_b \) for water = 0.512 K kg mol\(^{-1}\))

In case of association, abnormal molar mass of solute will:

An aqueous solution of NaOH was made and its molar mass from the measurement of osmotic pressure at 27°C was found to be 25 g mol$^{-1$.}
Calculate the percentage dissociation of NaOH in this solution.

Define Azeotrope. What type of Azeotrope is formed by negative deviation from Raoult's law? Give an example.

On mixing 30 mL of acetone with 20 mL of chloroform, the total volume of solution is:

Which of the following solutions will have the highest boiling point in water?

Assertion (A): Aquatic species are more comfortable in cold water than in warm water.
Reason (R): Solubility of oxygen gas in water decreases with increase in temperature.

Assertion (A): Cooking time is reduced in pressure cooker.
Reason (R): Boiling point of water inside the pressure cooker is elevated.

An unripe mango placed in a concentrated salt solution to prepare pickle, shrivels because __________

Give reasons:
(a) Cooking is faster in a pressure cooker than in an open pan.
(b) On mixing liquid X and liquid Y, volume of the resulting solution decreases. What type of deviation from Raoult's law is shown by the resulting solution? What change in temperature would you observe after mixing liquids X and Y?

0.3 g of acetic acid (Molar mass = 60 g mol\(^{-1}\)) dissolved in 30 g of benzene shows a depression in freezing point equal to 0.45°C. Calculate the percentage association of acid if it forms a dimer in the solution.
(Given: \( K_f \) for benzene = 5.12 K kg mol\(^{-1}\))

A solution of glucose (molar mass = 180 g mol\(^{-1}\)) in water has a boiling point of 100.20°C. Calculate the freezing point of the same solution. Molal constants for water \(K_f\) and \(K_b\) are 1.86 K kg mol\(^{-1}\) and 0.512 K kg mol\(^{-1}\) respectively.

Why can azeotropic mixture not be separated by fractional distillation?

What is meant by negative deviation from Raoult’s law? Give an example. What type of azeotrope is formed by negative deviation?