In the removal of water hardness, permutit is regenerated with a strong solution of

A.

NaOH

B.

Na\(_3\)SO\(_4\)

C.

Na\(_3\)CO\(_3\)

D.

NaCl

Correct answer is D

permutit water softener can be regenerated by washing the spent resin with brine( saturated sodium chloride solution). The solution ions replace the calcium or magnesium ions present in it.

\(CaR_{2(s)}\) + 2\(NaCl_{aq}\)  → \(CaCl_{2(aq)}\) + 2\(NaR_{2(s)}\)