Calculate the proportion of O₂ and N₂ dissolved in water at 298 K. When air containing 20% O₂ and 80% N₂ by volume is in equilibrium with it at 1 atm pressure. Henry’s law constants for two gases are K_H(O₂) = 4.6 x 10⁴ atm and K_H (N₂) = 8.5 x 10⁴ atm.

Calculate the mole fractions of benzene and naphthalene in the vapour phase when an ideal liquid solution is formed by mixing 128 g of naphthalene with 39 g of benzene. It is given that the vapour pressure of pure benzene is 50.71 mm Hg and the vapour pressure of pure naphthalene is 32.06 mmHg at 300 K.

An aqueous solution of 2% nonvolatile solute exerts a pressure of 1.004 bar at the boiling point of the solvent. What is the molar mass of the solute when P_A is 1.013 bar ?

2.56 g of Sulphur is dissolved in 100g of carbon disulphide. The solution boils at 319. 692 K. What is the molecular formula of Sulphur in solution The boiling point of CS₂ is 319. 450K. Given that K_b for CS₂ = 2.42 K Kg mol^-1.

Ethylene glycol (C₂H₆O₂) can be at used as an antifreeze in the radiator of a car. Calculate the temperature when ice will begin to separate from a mixture with 20 mass percent of glycol in water used in the car radiator. K_f for water = 1.86 K Kg mol^-1 and molar mass of ethylene glycol is 62 g mol^-1.

What is the mass of glucose (C₆ H₁₂O₆) in it one litre solution which is isotonic with 6 g L^-1 of urea (NH₂ CO NH₂) ?

A sample of 12 M Concentrated hydrochloric acid has a density 1.2 gL^–1 Calculate the molality.

Henry’s law constant for solubility of methane in benzene is 4.2 x 10^-5 mm Hg at a particular constant temperature At this temperature.
Calculate the solubility of methane at
i) 750 mm Hg
ii) 840 mm Hg

The observed depression in freezing point of water for a particular solution is 0.093^o C. Calculate the concentration of the solution in molality. Given that molal depression constant for water is 1.86 K Kg mol^-1.

The vapour pressure of pure benzene (C₆H₆) at a given temperature is 640 mm Hg. 2.2 g of non-volatile solute is added to 40 g of benzene. The vapour pressure of the solution is 600 mm Hg. Calculate the molar mass of the solute ?