Temporary hardness and permanent hardness can be removed by the sequential addition of which of the following?

The density of water is greater than that of ice because of

Discuss the principle and method of softening of hard water by synthetic ion-exchange.

Given below are two statements:
Statement-$I$: Permutit process is more efficient compared to the synthetic resin method for the softening of water.
Statement-$II$: Synthetic resin method results in the formation of soluble sodium salts.
In the light of the above statements,choose the most appropriate answer from the options given below:

Zeolite is hydrated sodium aluminium silicate. When treated with hard water,the sodium ions in zeolite are exchanged with

What properties of water make it useful as a solvent? What types of compounds can it $(i)$ dissolve and $(ii)$ hydrolyse?