Depression in Freezing Point

Author:Academic Experts
KVPY Aptitude Test - Stream SX
IMPORTANT

Important Questions on Depression in Freezing Point

MEDIUM
IMPORTANT

A solution containing 8.0 g of nicotine in 92 g of water freezes 0.925 degrees below the normal freezing point of water. If the molal freezing point depression constant, Kf=1.85°C mol-1, then the molar mass of nicotine is:

MEDIUM
IMPORTANT

The addition of 0.643 g of a compound to 50 ml of benzene (density =0.879 g mol-1) lowers the freezing point from 5.51°C to 5.03°C. If the freezing point constant, Kf, for benzene is 5.12 K kg mol-1, the molar mass of the compound is approximately:

HARD
IMPORTANT

The freezing point of pure benzene is 5.5 °C. When 2.9 g of butane is dissolved in 200 g of benzene, the freezing point of benzene decreases to 4 °C. To lower the freezing point of benzene by another 1.5 °C, the amount of butane that has to be added to mixture is:

MEDIUM
IMPORTANT

Determine the freezing point (in C) of a solution containing 0.1 g of K3FeCN6 (Mol. Wt. 329) in 100 g of water Kf=1.86 K kg mol-1.

MEDIUM
IMPORTANT

A complex of iron and cyanide ions is 100% ionised at 1 m (molal). If its elevation in the boiling point is 2.08. Then, the complex is Kb=0.52 °C mol-1 kg:

MEDIUM
IMPORTANT

A 0.2 molal aqueous solution of a weak acid HX is 20 percent ionised. The freezing point of this solution is: (Given Kf=1.86°C kg mol-1 for water)

MEDIUM
IMPORTANT

Aqueous solution of barium phosphate which is 100% ionised has ΔTf/Kf as 0.05. Hence, the given solution is:

MEDIUM
IMPORTANT

Which of the following has been arranged in the order of decreasing freezing point?