set 2 MCQ Questions & Answers Detailed Explanation

Question : 1

When iron is left exposed in open air, it gets rusted. Which constituent(s) of air is /are responsible for rusting iron?

1. Oxygen gas present in air
2. Moisture present in air
3. Carbon dioxide gas present in air

a) 1 and 2

b) 2 only

c) 1 only

d) 2 and 3

Question : 2

Which of the following statements about diamond are correct?

1. It is used as a gem in jewellery because of its ability to reflect light.
2. It is good conductor of electricity.
3. It is used for cutting glass, marble stones and other hard materials.
4. It is used for drilling of rocks.

a) 1, 2 and 3

b) 2, 3 and 4

c) 1, 3 and 4

d) 2 and 4

Question : 3

$H_2O$ is liquid and $H_2S$ is a gas because

a) atomic radius of oxygen is less than that of sulphur.

b) oxygen is less electronegative than sulphur.

c) oxygen forms stronger hydrogen bonding than sulphur.

d) atomic radius of oxygen is greater than that of sulphur.

Question : 4

Consider the following statements with reference to the periodic table of chemical elements.

1. Ionization potential gradually decreases along a period.
2. In a group of elements, electron affinity decreases as the atomic weight increases.
3. In a given period, electronegativity decreases as the atomic number increases.

a) Only 1

b) 1 and 3

c) Only 2

d) 2 and 3

Question : 5

Consider the following statements:
Hard water does not give lather with soap because hard water contains:

1. calcium bicarbonate
2. magnesium bicarbonate
3. chlorides of calcium and magnesium
4. sulphates of calcium and magnesium

a) 1, 2 and 3

b) 3 and 4

c) 1 and 2

d) 1, 2, 3 and 4

Question : 6

Which is the most abundant element after oxygen?

a) Silicon

b) Sodium

c) Carbon

d) Chlorine