Which of the following salts cause permanent hardness of water ?

1. Calcium sulphate
2. Calcium bicarbonate
3. Sodium chloride
4. Magnesium nitrate

The substance which can remove permanent hardness of water is :

1. sodium bicarbonate
2. sodium carbonate
3. sodium hydroxide
4. sodium chloride

Assertion (A): Water is a universal solvent.

Reason (R): We use water daily for drinking, washing, bathing, etc.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Water exists in all the three states of matter.

Reason (R): On cooling, liquid water changes into ice, the solid state. On heating, it changes into vapour, the gaseous state.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.