Show how the successive use of cation- and anionexchange resins could be used to remove sodium chloride from water.

To remove sodium chloride from water using cation- and anion-exchange resins, pass the solution through a cation-exchange resin first. The resin attracts and holds sodium ions (Na+), releasing an equivalent amount of hydrogen ions (H+) in exchange. Reaction: \(Na^+_{(aq)} + Resin^-H^+ \rightarrow Resin^-Na^+ + H^+_{(aq)}\) Then, pass the solution through an anion-exchange resin, which attracts and holds chloride ions (Cl-) and releases an equivalent amount of hydroxide ions (OH-) in exchange. Reaction: \(Cl^-_{(aq)} + Resin^+OH^- \rightarrow Resin^+Cl^- + OH^-_{(aq)}\) Finally, the hydrogen ions (H+) and hydroxide ions (OH-) present in the solution combine to form water (H2O), effectively removing sodium chloride and leaving purified water. Reaction: \(H^+_{(aq)} + OH^-_{(aq)} \rightarrow H_2O_{(l)}\)