Solutions

The elevation in boiling point for 1 molal solution of non-volatile solute A is 3K. The depression in freezing point for 2 molal solution of A in the same solvent is 6 K. The ratio of K_b and K_f i.e. K_b/K_f is 1 : X. The value of X is [nearest integer]

Match List – I and List – II.

Choose the correct answer from the options given below

A gaseous mixture of two substances A and B, under a total pressure of 0.8 atm is in equilibrium with an ideal solution. The mole fraction of substance A is 0.5 in the vapour phase and 0.2 in the liquid phase. The vapour pressure of pure liquid A is_________atm. (Nearest integer)

At $300\mathrm{K}$ , the vapour pressure of a solution containing 1 mole of $n$ -hexane and 3 moles of $\mathrm{n}$ -heptane is $550\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . At the same temperature, if one more mole of $\mathrm{n}$ -heptane is added to this solution, the vapour pressure of the solution increases by $10\mathrm{m}\mathrm{m}$ of $\mathrm{H}\mathrm{g}$ . What is the vapour pressure in $\mathrm{m}\mathrm{m}\mathrm{H}\mathrm{g}$ of $n$ -heptane in its pure state ?

The vapour pressure of two volatile liquid A and B at 25°C are 50 Torr and 100 Torr, respectively. If the liquid mixture contains 0.3 mole fraction of A, then the mole fraction of liquid B in the vapour phase is $\frac{x}{17}.$ <!-- [if gte mso 9]><xml> </xml><![endif]--> The value of x is____________.

If O₂ gas is bubbled  through water at 303 K, the number of millimoles of O₂ gas that dissolve in 1 litre of water is______________. (Nearest integer)

(Given: Henry’s Law constant for O₂ at 303 K is 46.82 k bar and partial pressure of O₂ = 0.920 bar)

(Assume solubility of O₂ in water in too small, nearly negligible)

The osmotic pressure of a solution of $\mathrm{N}\mathrm{a}\mathrm{C}\mathrm{l}$ is $0.10\mathrm{a}\mathrm{t}\mathrm{m}$ and that of a glucose solution is $0.20\mathrm{a}\mathrm{t}\mathrm{m}$ . The osmotic pressure of a solution formed by mixing $1\mathrm{L}$ of the sodium chloride solution with $2\mathrm{L}$ of the glucose solution is $\mathrm{x}\times {10}^{-3}\mathrm{a}\mathrm{t}\mathrm{m}.\mathrm{x}$ is (nearest integer)(Solutions)

A $100\mathrm{m}\mathrm{L}$ solution was made by adding $1.43\mathrm{g}$ of ${\mathrm{N}\mathrm{a}}_2{\mathrm{C}\mathrm{O}}_3\cdot {\mathrm{x}\mathrm{H}}_2\mathrm{O}$ . The normality of the solution is $0.1\mathrm{N}$ . The value of $x$ is (The atomic mass of $\mathrm{N}\mathrm{a}$ is $23\mathrm{g}/\mathrm{m}\mathrm{o}\mathrm{l}$ )

A solution containing 2.5 × 10^-3 kg of solute dissolved in 75 × 10^-3 kg of water boils at 373.535 K. The molar mass of the solute is_________g mol^-1. (nearest integer)

[Given K_b(H₂O) = 0.52 K kg mol^-1 and boiling point of water = 373.15 K)

Assertion: When a solution is separated from the pure solvent by a semipermeable membrane, the solvent molecules pass through it from pure solvent side to the solution side.

Reason: Diffusion of solvent occurs from a region of high concentration solution to a region of low concentration solution.