Chemistry Top MCQs – 12

The half life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind?
(A) 1/6
(B) 1/3
(C) 1/8
(D) 1/4
Answer: Option C

The maximum number of covalent formed by nitrogen is
(A) 1
(B) 2
(C) 3
(D) 4
Answer: Option D

The metal that is usually extracted from sea water is
(A) Ca
(B) Na
(C) K
(D) Mg
Answer: Option D

Potassium nitrate is used in
(A) Medicine
(B) Fertiliser
(C) Salt
(D) Glass
Answer: Option B

What is laughing gas?
(A) Nitrous Oxide
(B) Carbon monoxide
(C) Sulphur dioxide
(D) Hydrogen peroxide
Answer: Option A

Soda water contains
(A) Carbonic acid
(B) Sulphuric acid
(C) Carbon dioxide
(D) Nitrous acid
Answer: Option C

Marsh gas is
(A) Nitrogen
(B) Ethane
(C) Methane
(D) Hydrogen
Answer: Option C

LPG consists of mainly
(A) Methane, ethane and hexane
(B) Ethane, hexane and nonane
(C) Methane, hexane and nonane
(D) Methane, butane and propane
Answer: Option D

Most soluble in water is
(A) Camphor
(B) Sulphur
(C) Common salt
(D) Sugar
Answer: Option D

Permanent hardness of water may be removed by the addition of
(A) Sodium carbonate
(B) Alum
(C) Potassium permanganate
(D) Lime
Answer: Option A