Depression in Freezing Point of the Solvent

IMPORTANT

Depression in Freezing Point of the Solvent: Overview

This topic covers concepts, such as, Depression in Freezing Point, Molal Freezing Point Depression Constant, Anti-Freezing Agents & Molal Freezing Point Depression Constant Using Molar Heat of Fusion etc.

Important Questions on Depression in Freezing Point of the Solvent

HARD
IMPORTANT

What mass of ethylene glycol (molar mass =62.0g​ mol1)  must be added to 5.50 kg of water to lower the freezing point of water from  0°C to10.0°C?  (Kf  forwater=1.86Kkgmol1)

HARD
IMPORTANT

Calculate the depression in the freezing point of water when 10 g of  CH3CH2CHClCOOH is added to 250 g of water.  Ka=1.4×103, Kf=1.86 K kg mol1.

HARD
IMPORTANT

Calculate the freezing point of a solution containing 18 g glucose, C6H12O6and68.4gsucrose,C12H22O11in200g of water. The freezing point of pure water is 273 K and Kf for water is 1.86 K kg mol1.

HARD
IMPORTANT

The freezing point of a solution containing 0.2 g of acetic acid in 20.0 g of benzene is lowered by 0.45°C. The molar mass (g/mol) of acetic acid from this data and the value of van’t Hoff factor would be (for benzene, Kf=5.12 K kg mol-1)

EASY
IMPORTANT

Assertion: Camphor is usually used in molecular mass determination.

Reason: Camphor has low cryoscopic constant and therefore, causes greater depression in freezing point.

EASY
IMPORTANT

Assertion: Sodium chloride is used to clear snow on the roads.

Reason :Sodium chloride depresses the freezing point of water.

MEDIUM
IMPORTANT

Give some examples of anti-freezing agents.

MEDIUM
IMPORTANT

What are anti-freezing agents?

EASY
IMPORTANT

Which of the following statements is false?

HARD
IMPORTANT

31 g of an unknown molecular material is dissolved in 500 g of water. The resulting solution freezes at 271.14 K. Calculate molar mass of the material in gmol-1.(KfH2O = 1.86 K kg mol-1 , TofH2O= 273K)

MEDIUM
IMPORTANT

The depression in freezing point of 0.01 m aqueous solution of urea, sodium chloride and sodium sulphate is in the ratio :

HARD
IMPORTANT

Which is the correct relationship between molal depression constant and enthalpy of fusion ?

HARD
IMPORTANT

1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol-1. Find the molar mass of the solute.

HARD
IMPORTANT

The observed depression in freezing point of water for a particular solution is 0.093 K. Calculate the concentration of the solution in molality. Given that molal depression constant for water is 1.86 K kg mol-1. (Write only numerical value and round upto two decimal places)

EASY
IMPORTANT

Define molal depression constant. How is it related to enthalpy of fusion?

MEDIUM
IMPORTANT

Which of the following will have maximum depression in freezing point?

MEDIUM
IMPORTANT

How molar mass of a non-volatile solute is related to the depression in freezing point? Derive an equation.

EASY
IMPORTANT

What causes depression in freezing point?

MEDIUM
IMPORTANT

Calculate the temperature at which the solution (of 54 g glucose in 250 g water) freezes. Kf= 1.86 K Kg mol-1.

EASY
IMPORTANT

Which of the following solutions contains the maximum freezing point?