Chemistry Top MCQs – 2

The oldest rocks in the earth’s crust were once molten, and came from deep inside the earth. The molten rock, called magma, spewed out in volcanic eruptions during the earth’s early life and solidified into hard rock’s called
(A) Granite
(B) Basalt
(C) Igneous rocks
(D) Sedimentary rocks
Answer: Option C

The heat required to raise the temperature of body by 1K is called
(A) Specific heat
(B) Thermal capacity
(C) Water equivalent
(D) None of the above
Answer: Option B

The Latin word ‘Formica’ means ant. The name formic acid is derived from this Latin word because
(A) This acid, in ancient times, was used to eliminate ant-hills
(B) This corrosive acid is secreted by ants to drive away their enemies
(C) This acid was first obtained by the distillation of ants
(D) Ants are attracted by the odour of this acid
Answer: Option C

The heat energy produced when the human body metabolises 1 gram of fat is
(A) 30 KJ
(B) 1 KJ
(C) 39 KJ
(D) 29 KJ
Answer: Option C

The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is
(A) 1.568 × 103
(B) 6.023 × 1019
(C) 4.84 × 1017
(D) 6.023 × 1023
Answer: Option B

The mass number of a nucleus is
(A) Always less than its atomic number
(B) The sum of the number of protons and neutrons present in the nucleus
(C) Always more than the atomic weight
(D) A fraction
Answer: Option B

The method that cannot be used for removing permanent hardness of water is
(A) Adding sodium carbonate
(B) Distillation
(C) Adding caustic soda
(D) Boiling
Answer: Option D

The molecule which has the highest percentage of ionic character among the following is
(A) HI
(B) HF
(D) HBr
Answer: Option B

The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2nd orbit to 3rd orbit is
(A) 5x/36
(B) 5x
(C) 7.2 x
(D) x/6
Answer: Option A

The mineral containing both magnesium and calcium is
(A) Magnesite
(B) Calcite
(C) Carnallite
(D) Dolomite
Answer: Option D