JAMB - Chemistry (2018 - No. 84)
In the removal of water hardness, permutit is regenerated with a strong solution of
NaOH
Na\(_3\)SO\(_4\)
Na\(_3\)CO\(_3\)
NaCl
Paskaidrojums
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\(NaR_{2(s)}\)