Previous 10 Years Question Papers with Answers for TRB Chemistry - 3

Question: 11

Which among the following is an element?

(A) Silica

(B) Alumina

(C) Brass

(D) Graphite

Question: 12

Alum purifies muddy water by

(A) Absorption

(B) Dialysis

(C) Emulsification

(D) Coagulation

Question: 13

The biocatalyst are

(A) Enzymes

(B) Minerals

(C) Plants

(D) All proteins

Question: 14

When CO₂ is passed through an aqueous solution of bleaching powder, the gas evolved is

(A) Chlorine dioxide

(B) Chlorine

(C) Oxygen

(D) Ozone

Question: 15

Which one of the following metals occurs in nature in free state?

(A) Aluminium

(B) Gold

(C) copper

(D) Sodium