set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

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 : 2

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 : 3

Slow eating away of iron articles in the presence of moist air is called

a) rusting

b) galvanisation

c) crystallisation

d) neutralisation

Question : 4

Which one is a decomposition reaction ?

a) 2H₂O $⟶ ↖ {Electrolysis}$ 2H₂ + O₂

b) 2HgO $⟶ ↖ {heat}$ 2Hg + O₂

c) CaCO₃ $⟶ ↖ {heat}$ CaO + CO₂

d) All the above reactions are decomposition reaction

Question : 5

An organic compound containing C, H and O gave on analysis C – 40% and H – 6.66%. Its empirical formula would be

a) CH₂O

b) C₃H₆O

c) CHO

d) CH₄O

Question : 6

Valency of an atom or radicals is

a) its combining capacity

b) ionisation energy

c) electron affinity of atom

d) size of atom