Zeolites are used as
a) ion exchangers
b) molecular sieves
c) water softener
The correct uses are

The structure of Zeolite permits the formation of cavities of different sizes.

Molecules like Water, NH₃ , CO₂and ethanol are trapped in these cavities.

Hence Zeolites acts as molecular sieves.

 In sheet silicates , one-fourth or one-half of Silicon ions are replaced by Al⁺³ ions , then Zeolite  formed

They trap Ca⁺² ions from hard water and replace Na⁺  ions, hence acts as ion exchanger.

2NaZ_(s) + M⁺² _(aq.) →MZ_{2 (s)} + 2Na⁺   _(aq.)  [ M = Mg , Ca ]

 Sodium Zeolite is used to remove permanent hardness of water(used as water softner).

the formula of Zeolite is Na₂Al₂Si₂O₈ .xH₂O (or) simply NaAlSiO₄ (or) NaZ, which is Known as sodium aluminium silicate.