Practice MCQ Questions and answers on Chemistry-GK

21

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

Discuss

Answer & Solution

Answer: Option C

Solution:

The Latin word formica means ant. The name formic acid is derived from this Latin word because this acid was first obtained by the distillation of ants.

22

The ore which is found in abundance in India is

A) monazite B) fluorspar C) bauxite D) magnetite

Discuss

Answer & Solution

Answer: Option A

Solution:

The ore which is found in abundance in India is monazite.

23

The inherited traits of an organism are controlled by

A) RNA molecules B) nucleotides C) DNA molecules D) enzymes

Discuss

Answer & Solution

Answer: Option C

Solution:

The inherited traits of an organism are controlled by DNA molecules.
The traits an organism displays are ultimately determined by the genes it inherited from its parents, in other words by its genotype. Animals have two copies of all their chromosomes, one from each parent.

24

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

Discuss

Answer & Solution

Answer: Option C

Solution:

The heat energy produced when the human body metabolises 1 gram of fat is 39 KJ.

25

What are the number of moles of CO₂ which contains 16 g of oxygen?

A) 0.5 mole B) 0.2 mole C) 0.4 mole D) 0.25 mole

Discuss

Answer & Solution

Answer: Option A

Solution:

One mole of CO₂ has mass of 44 g and 32 g of O₂.
So 16 g of O₂ have 22 g of CO₂ or 0.5 moles of it.

26

The main use of salt in the diet is to

A) make the taste of food better B) produce in small amounts the hydrochloric acid required for the digestion of food C) ease the process of cooking D) increase the solubility of food particles in water

Discuss

Answer & Solution

Answer: Option B

Solution:

The main use of salt in the diet is to produce in small amounts the hydrochloric acid required for the digestion of food.

27

The monomer of polythene is

A) vinyl chloride B) ethylene C) ethyl alcohol D) None of the above

Discuss

Answer & Solution

Answer: Option B

Solution:

Polyethylene is the most common plastic. The monomer is ethylene, a gaseous hydrocarbon with the formula C₂H₄ which can be viewed as a pair of methylene groups connected to each other.

28

The luster of a metal is due to

A) its high density B) its high polishing C) its chemical inertness D) presence of free electrons

Discuss

Answer & Solution

Answer: Option D

Solution:

Metallic lustre is due to the mobile electrons present in metals which when de-excites releases energy in the form of light.

29

The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is

A) 1.568 x 10³ B) 6.023 x 10¹⁹ C) 4.84 x 10¹⁷ D) 6.023 x 10²³

Discuss

Answer & Solution

Answer: Option B

Solution:

The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is 6.023 x 10¹⁹.

30

The most malleable metal is

A) platinum B) silver C) iron D) gold

Discuss

Answer & Solution

Answer: Option D

Solution:

The most malleable metal is gold.