Chemistry Question Bank

What weight of glycerol should be added to 600 g of water in order to lower its freezing point by 10ºC? (Kf = 1.86ºC m–1). (Molecular mass of glycerol is 92)

The molar freezing point constant for water is 1.86º C/m. If 342g of cane sugar (C₁₂H₂₂O₁₁) is dissolved in 1000 g of water, the solution will freeze at

The freezing point of 1 molal Glucose solution in water is ( 1.86 H O f K K kg mol )

What would happen if a thin slice of sugar beet is placed in a concentrated solution of NaCl?

0.2 molal acid HX ionises 20%. Kf for acid is 1.86 molality–1. Freezing point is

Sprinkling of salt helps in clearing the snow covered roads in hills. The phenomenon involved in the process is

An aqueous solution freezes at –2.550C. What is its boiling point. 0.52 / ; 1.86 / ? H O H O b f K K m K K m

Given that Tf is the depression in freezing point of the solvent in a solution of a nonvolatile solute of molality 1, the quantity f m T lt m → is equal to

Elevation in boiling point was 0.520C when 6 gm of a compound X was dissolved in 100 gm of water. Molecular weight of X is (Kb of water is 0.52 K⁻ kg/mol)

If the elevation in boiling point of a solution of 10gm of solute (mol. wt. = 100) in 100 gm of water is bT , then ebullioscopic constant of water is

The molal b.p. constant for water is 0.5130C kg mol– 1. When 0.1 mole of sugar is dissolved in 200 g of water, the solution boils under a pressure of 1 atm at

The freezing point of a 0.05 molal solution of a non- electrolyte in water is

An aqueous solution containing 1g of urea boils at 100.25ºC. The aqueous solution containing 3g of glucose in the same volume will boil at

At certain hill-station, pure water boils at 99.725ºC. If Kb for water is 0.513ºC kg mol–1, the boiling point of 0.69m solution of urea will be

If 1g of solute (molar mass = 50g mol–1) is dissolved in 50g of solvent and the elevation in boiling point is 1K. The molar boiling constant of the solvent is

The vapour pressure of acetone at 20°C is 185 torr. When 1.2g of a non-volatile substance was dissolved in 100 g of acetone at 20°C, its vapour pressure was 183 torr. The molar mass (g mol–1) of the substance is:

18 g glucose (C₆H₁₂O₆) is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is:

A solution containing 12.5g of non-electrolyte substance in 185g of water shows boiling point elevation of 0.80 K. Calculate the molar mass of the substance. SOLUTIONS (Kb = 0.52 K kg mol-1)

The boiling point of 0.1 molal aqueous solution of urea is 100.18ºC at 1 atm. The molal elevation constant of water is

Pure benzene freezes at 5.45ºC at a certain place but a 0.374m solution of tetrachloroethane in benzene freezes at 3.55ºC. The Kf for benzene is

Relative lowering of vapour pressure of a dilute solution is 0.2 what is the mole fraction of the non- volatile solute?

The vapour pressure of pure solvent is 0.8 mm of Hg at a particular temperature. On addition of a non-volatile solute ‘A’ the vapour pressure of solution becomes 0.6 mm of Hg. The mole fraction of component ‘A’ is

If at certain temperature, the vapour pressure of pure water is 25 mm Hg and that of a very dilute aqueous urea solution is 24.5 mm Hg, the molality of the solution is

In a solution of 7.8 g of benzene (C₆H₆) and 46 g of toluene (C₆H₅CH₃), the mole fraction of benzene is

Vapour pressure of a pure liquid X is 2 atm at 300 K. It is lowered to 1 atm on dissolving 1g of Y in 20g of liquid X. If molar mass of X is 200, what is the molar mass of Y?