Question

When zeolite (hydrated sodium aluminium silicate) is treated with hard water the sodium ions are exchanged with
(a) H⁺ ions
(b) Ca²⁺ ions
(c) $SO_4^{2-}$ ions
(d) OH⁻ ions

Answer 1

(b) Ca²⁺ ion

Na2Z + CaCl2 = CaZ + 2NaCl