Explain the zeolite process of water softening?
Answers
When Ca2+ and Mg2+ ions containing hard water is passes through a bed of sodium zeolite, the sodium ions are replace by the calcium and magnesium ions.
Calcium (Ca) and Magnesium (Mg) are mainly responsible for the hardness of the water. Hard water containing Ca and Mg is passed through zeolite. When the water passes through the Zeolite, exchange of ions takes place i.e. Calcium and Magnesium react with zeolite to form Sodium and Aluminium compounds.
Zeolite is also called as Hydrated Sodium Alumino Silicate. The chemical formula of a zeolite is Na2O. Al2O3. aSiO2. bH2O. Zeolite is made up of micro-porous minerals which have the capacity of exchanging ions. Hence zeolite is used to removes the hardness of the water as zeolite contains Sodium and Aluminium
The reaction involved in this process are as follows:
CaX + 2NaCl = Na₂X + CaCl₂
MgX + 2NaCl = Na₂X + MgCl₂
where CaX and MgX are compounds of calcium and magnesium.