Solubility product (K_sp) of saturated PbCl₂ in water is 1.8 × 10^-4 mol³ dm^-9. What is the concentration of Pb²⁺ in the solution?

• (0.45 × 10^-4)^1/3 mol dm^-3

• (1.8 × 10^-4)^1/3 mol dm^-3

• (0.9 × 10^-4)^1/3 mol dm^-3

• (2.0 × 10^-4)^1/3 mol dm^-3

The freezing point of equimolal solution will be highest for

• C₆H₅NH₃Cl

• D- fructose

• AgNO₃

• Ca(NO₃)₂

One mole of an unknown compound was treated with excess water and resulted in the evolution of two moles of a readily combustible gas. The resulting solution was treated with CO₂ and resulted in the formation of white turbidity. The unknown compound is

• Ca

• CaH₂

• Ca(OH)₂

• Ca(NO₃)₂

If the boiling point difference between that two liquids is not much, the ............ method is used to separate them

• Simple distillation

• Distillation under reduced pressure

• Steam distillation

• Differential extraction

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

76.

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