Softening of hard water is done using sodium aluminium silicate (zeolite) . This causes

Options

A. adsorption of `Ca^(2+)` and `Mg^(2+)` ions of hard water replacing `Na^(+)` ions.
B. adsorption of `Ca^(2+)` and `Mg^(2+)` ions of hard water replacing `Al^(3+)` ions.
C. both (a) and (b)
D. none of these

Answer

A

Explanation

Softening of hard water: ion exchange resisns used for softening of hard water is based upon sensitive and competitive adsorption of ions on resins.
`Na_(2)Z+Ca^(2+) rarr CaZ+2Na^(+)`
the organic polymers containing groups like
`-COOH, -SO_(3)H` and `-NH_(2)`, etc. possess the property of selective adsorption of ions from solution. These are quite useful in the softening of water.