Answer to Question #334939 in General Chemistry for Mai

Question

In basic solution, hypochlorite ions, oxidize chromite ions, to chromate ions, and are reduced to chloride ions. Write the balanced net ionic equation for this reaction.

Answer 1

We are given the formulas for two reactants and two products; we write as much of the equations as possible. The reaction occurs in basic solution; we can add OH^- and H₂O as needed. We construct and balance the appropriate half-reactions, equalize the electron transfer add the half-reactions, and eliminate common terms.

CrO₂^- + ClO^- -> CrO₄^2- + Cl^-

CrO₂^- -> CrO₄^2- (ox. half-rxn)

CrO₂^- + 4OH^- -> CrO₄^2- + 2H₂O

CrO₂^- + 4OH^- -> CrO₄^2- + 2H₂O + 3e^- (balanced ox. half-rxn)

ClO^- -> Cl^- (red. half-rnx)

ClO^- + H₂O -> Cl^- + 2OH^-

ClO^- + H₂O + 2e^- -> Cl^- + 2OH^- (balanced red. half-rnx)