Chemistry MCQs Class 11 – Page 2 – Quiz

What will be the correct order of vapour pressure for water, acetone and ether at 30°C. Given that among these compounds, water has maximum boiling point and ether has minimum boiling point?

(A) Water < ether < acetone
(B) Water < acetone < ether
(C) Ether < acetone < water
(D) Acetone < ether < water

Answer: (C) Ether < acetone < water

Oxidation number of S in Na2S2O3 is:

(A) +1
(B) +2
(C) +3
(D) +4

Answer: (B) +2

The sum of enthalpy changes during a chemical reaction of more than one step is zero. This is called:

(A) Charles law
(B) Faraday’s law
(C) Avogadro’s law
(D) Hess’s law

Answer: (D) Hess’s law

Molarity of pure water is:

(A) 1 mol/dm³
(B) 1.8 mol/dm³
(C) 55.5 mol/dm³
(D) 18 mol/dm³

Answer: (C) 55.5 mol/dm³

The order of a chemical reaction is Two. It means that:

(A) The rate of reaction increases twice if the concentration of reactant is
doubled.
(B) The rate of reaction increases four times if the concentration of reactant is
doubled.
(C) The rate of reaction is independent of the concentration of reactant
(D) The rate of reaction decreases when the concentration of reactant is
doubled

Answer: (B) The rate of reaction increases four times if the concentration of reactant is
doubled.