31 g of ethylene glycol (C₂H₆O₂) is mixed with 500 g of solvent (K_f of the solvent is 2 K kg mol^-1 ). What is the freezing point of the solution (in K)? (Freezing point of solvent = 273 K)

• 272

• 271

• 270

• 274

Which one of the following binary liquid mixture exhibit positive deviation from Raoult's law?

• Carbon disulphide-acetone

• Chloroform-acetone

• Bromobenzene-chlorobenzene

• Benzene-toluene

An aqueous solution containing 3 g of a solute of molar mass 111.6 g mol^-1 in a certain mass of water freezes at -0.125°C. The mass of water in grams present in the solution is (K_f =1.86 K kg mol^-1)

• 300

• 600

• 500

• 400

In neutral or faintly alkaline medium, thiosulphate is quantitatively oxidized by KMnO₄ to

• SO${}_3^{2-}$

• SO${}_4^{2-}$

• SO₂

• SO${}_5^{2-}$

If the elevation in boiling point of a solution of non-volatile, non-electrolytic and non-associating solute in a solvent (K_b = x K kg mol^-1) is y K, then the depression in freezing point of solution of same concentration would be (K_f of the solvent = z K kg mol^-1)

• $\frac{2xz}{y}$

• $\frac{yz}{x}$

• $\frac{xz}{y}$

• $\frac{yz}{2x}$

The vapour pressure of pure benzene and toluene at a particular temperature are 100 mm and 50 mm respectively. Then the mole fraction of benzene in vapour phase in contact with equimolar solution of benzene and toluene is 

• 0.67

• 0.75

• 0.33

• 0.50

The relation between solubility of a gas in liquid at constant temperature and external pressure is stated by which law?

• Raoult's law

• van't Hoff- Boyle's law

• van't Hoff- Charles' law

• Henry's law

Identify the compound amongst the following of which 0.1 M aqueous solution has highest boiling point.

• Glucose

• Sodium chloride

• Calcium chloride

• Ferric chloride

Freezing point of an aqueous solution is -0.186°C. If the values of K_b and K_f of water are respectively 0.52 K kg mol^-1 and 1.86 K kg mol^-1 then the elevation of boiling point of the solution in K is

• 0.052

• 0.52

• 1.04

• 1.34

The correct order of boiling points of 2, 2-dimethylpropane, 2-methylbutane and n-pentane is

• n-pentane > 2, 2-dimethylpropane > 2-methylbutane

• n-pentane > 2-methylbutane >  2, 2-dimethylpropane

• 2, 2-dimethylpropane > 2-methylbutane > n-pentane 

• 2-methylbutane > 2, 2-dimethylpropane > n-pentane