Give reason:

On opening a bottle of cold drink, a fizz sound is heard.

The salt which gives water vapour on heating is called :

1. Hydrated
2. Hygroscopic
3. Deliquescent
4. Anhydrous

The substance which can remove permanent hardness of water is :

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

Temporary hardness of water can be removed by

1. filtering
2. boiling
3. loading
4. none of the above