set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is formed. This is an example of

a) decomposition reaction

b) combination reaction

c) displacement reaction

d) double decomposition reaction

Question : 2

CuO + H₂ ⟶ Cu + H₂O Above reaction is an example of

a) neutralisation reaction

b) Redox reaction

c) synthesis reaction

d) decomposition reaction

Question : 3

Which of the following statements is not correct?

a) A chemical equations tells us about the atom or molecules of the reactants and products involved in a reaction

b) A chemical equations tells us about the substances involved in a reaction.

c) A chemical equations informs us about the symbols and formula of substances involved in a reaction

d) All are correct

Question : 4

A redox reaction is one in which -

a) an acid is neutralised by the base

b) both the substance are reduced

c) both the substance are oxidised

d) one substance is oxidised while the other is reduced

Question : 5

The chromate and dicharomate ions are respectively

a) CrO^-₄ and CrO^-₅

b) CrO^2-₄ and Cr₂O^2-₇

c) Cr₂O^2-₇and CrO_4-

d) CrO^2-₄ and Cr₂O^2-₅

Question : 6

$Na_2S_2O_3$ represent the compound

a) sodium thiosulphate

b) sodium sulphate

c) sodium sulphite

d) None of these