Question

Which of the following is used in softening of water?

• A. Aluminium borate
• B. Aluminium silicate
• C. Silicones
• D. Chlorosilanes

Answer 1

The correct option is B Aluminium silicate

If Al atoms replace few Si atoms in 3D-network of $Si{O}_2$, overall structure known as aluminosilicate. These are called Zeolites. These silicates are negative charged so they are balance by cations like $N{a}^{+},K^{+}$.
These hydrated zeolites are used as ion exchangers in softening of “hard” water.
Sodium aluminium silicates, $N{a}_{2}A{l}_{2}S{i}_2{O}_8,$ which is mainly used to remove the hardness of water.

THEORY
Zeolites: Zeolites are microporous, aluminosilicate minerals. Commonly used as commercial adsorbent and catalysts.
If Al atoms replace few Si atoms in 3D-network of $Si{O}_2$, overall structure known as aluminosilicate. These are called Zeolites. These silicates are negative charged so they are balance by cations like $N{a}^{+},K^{+}$.

• These hydrated zeolites are used as ion exchangers in softening of “hard” water.
• Sodium aluminium silicates, $N{a}_{2}A{l}_{2}S{i}_2{O}_8,$ which is mainly used to remove the hardness of water.
• Zeolites are widely used as a catalyst in petrochemical industries for the cracking of hydrocarbons and isomerization. Hydrated zeolites are used as ion exchangers in softening “hard” water.
• ZSM-5 (A type of zeolite) used to convert alcohols directly into gasoline.