On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components (heptane and octane) are 105 kPa and 45 k_Pa respectively.Vapour pressure of the solution obtained by mixing 25.0 g of heptane and 35 g of octane will be (molar mass of heptane = 100 g mol^–1 and of octane =114 g mol^–1)

• 144.5 kPa

• 72.0 kPa

• 36.1 kPa

• 36.1 kPa

The freezing point of benzene decreases by 0.45°C when 0.2 g of acetic acid is added to 20 g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be
(K_f for benzene = 5.12 K kg mol^–1)

• 64.6% 

• 80.4%

• 74.6%

• 74.6%

On treatment of 100 mL of 0.1 M solution of CoCl₃ . 6H₂O with excess AgNO₃; 1.2 × 10²² ions are precipitated. The complex is

• [Co(H₂O)₄ Cl₂]Cl.2H₂O

• [Co(H₂O)₃Cl₃].3H₂O

• [Co(H₂O)₆]Cl₃

• [Co(H₂O)₆]Cl₃

1 gram of a carbonate (M₂CO₃) on treatment with excess HCl produces 0.01186 mole of CO₂. The molar mass of M₂CO₃ in g mol^-1 is

• 1186

• 84.3

• 118.6

• 118.6

Two liquids X and Y form an ideal solution. At 300 K, the vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550mm Hg. At the same temperature, if 1 mol of Y is further added to this solution, the vapour pressure of the solution increases by 10 mm Hg. Vapour pressure (in mmHg) of X and Y in their pure states will be respectively

• 200 and 300

• 300 and 400

• 400 and 600

• 400 and 600

A binary liquid solution is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution?

• The solution formed is an ideal solution

• The solution is non-ideal, showing +ve deviation from Raoult’s law.

• The solution is non-ideal, showing –ve deviation from Raoult’s law.

• The solution is non-ideal, showing –ve deviation from Raoult’s law.

At 80^o C, the vapour pressure of pure liquid ‘A’ is 520 mm Hg and that of pure liquid ‘B’ is 1000 mm Hg. If a mixture solution of ‘A’ and ‘B’ boils at 80^o C and 1 atm pressure, the amount of ‘A’ in the mixture is (1 atm = 760 mm Hg)

• 52 mol percent

• 34 mol percent

• 48 mol percent

• 48 mol percent

The vapour pressure of water at 20^oC is 17.5 mm Hg. If 18 g of glucose (C₆H₁₂O₆) is added to 178.2 g of water at 20^oC, the vapour pressure of the resulting solution will be

• 17.675 mm Hg

• 15.750 mm Hg

• 16.500 mm Hg

• 16.500 mm Hg

Equal masses of methane and oxygen are mixed in an empty container at 25ºC. The fraction of the total pressure exerted by oxygen is

• 2/3

• (1/3) x (273 / 298)

• 1/3

• 1/3

A 5.25% solution of a substance is isotonic with a 1.5% solution of urea (molar mass = 60 g mol^–1) in the same solvent. If the densities of both the solutions are assumed to be equal to 1.0 gcm^–3, molar mass of the substance will be –

• 90.0g mol^–1

• 115.0g mol^–1

• 105.0g mol^–1

• 105.0g mol^–1