Balance the following redox reaction by inserting the appropriate coefficients.
H+ + CrO42- + NO2- → Cr3+ + H2O +NO3-
We’re being asked to balance the given oxidation-reduction reaction:
H+ + CrO42– + NO2–→ Cr3+ + H2O + NO3–
We assume that the redox is in acidic solution since H+ is present. When balancing redox reactions under acidic conditions, we will follow the following steps.
Step 1: Separate the whole reaction into two half-reactions.
Step 2: Balance the non-hydrogen and non-oxygen elements first.
Step 3: Balance oxygen by adding H2O to the side that needs oxygen. (1 O: 1 H2O)
Step 4: Balance hydrogen by adding H+ to the side that needs hydrogen. (1 H: 1 H+)