At same temperature which pair of the following solutions are isotonic ?

• 0.2 M BaCl₂ and 0.2 M urea

• 0.1 M urea and 0.1 M NaCl

• 0.1 M NaCl and 0.1 M K₂SO₄

• 0.1 M Ba(NO₃)₂ and 0.1 M Na₂SO₄

Which is not a colligative property ?

• Refractive index

• Lowering of vapour pressure

• Depression in freezing point

• Elevation in boiling point

Assertion : A non volatile solute is mixed in a solution then elevation in boiling point and depression in freezing point both are 2 K.

Reason : Elevation in boiling point and depression in freezing point both depend on melting point of non-volatile solute.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

294.

The mass of glucose that should be dissolved in SO g of water in order to produce the same lowering of vapour pressure as is produced by dissolving 1 g of urea in the same quantity of water is :

• 1 g

• 3 g

• 6 g

• 18 g

Osmotic pressure observed when benzoic acid is dissolved in benzene is less than that expected from theoretical considerations .This is because :

• benzoic acid is an organic solute

• benzoic acid has higher molar mass than benzene

• benzoic acid gets associated in benzene

• benzoic acid gets dissociated in benzene

For a dilute solution, Raoult's law states that

• the relative lowering of vapour pressure is proportional to the amount of solute in solution

• the relative lowering of vapour pressure is equal to the mole fraction of solute

• the lowering of vapour pressure is equal to the mole fraction of the solute

• the vapour pressure of the solution is equal to the mole fraction of the solvent.

To a 25 mL H₂O₂ solution, excess of acidified solution of Kl was added. The iodine liberated required 20 ml of 0.3 N Na₂S₂O₃ solution. The volume strength of H₂O₂ solution is

• 1.344 g/L

• 3.244 g/L

• 5.4 g/L

• 4.08 g/L

A 0.1 molal solution of an acid is 4.5% ionized. Calculate freezing point. (molecular weight of the acid is 300). K_f = 1.86 K mol^-1 kg.

• -0.194$°$C

• 2.00$°$C

• 0$°$C

• -0.269$°$C

A mixture of two miscible liquids A and B is distilled under equilibrium conditions at 1 atm pressure. The mole fraction of A in solution and vapour phase are 0.30 and 0.60 respectively. Assuming ideal behaviour of the solution and the vapour, calculate the ratio of the vapour pressure of pure A to that of pure B.

• 4.0

• 3.5

• 2.5

• 1.85

1 mol each of the following compounds is dissolved in 1L of solution. Which will have the largest $∆{\mathrm{T}}_{\mathrm{b}}$ value?

• HF

• HCl

• HBr

• HI