Balancing Redox Reaction Video Lessons

Concept

Problem: Balance each of the following redox reactions occurring in basic solution. a. H2O2(aq) + ClO2(aq) → ClO2-(aq) +O2(g)b. Al(s)+MnO4-(aq) → MnO2(s) + Al(OH)4-(aq)c. Cl2(g) → Cl−(aq)+ ClO−(aq)

FREE Expert Solution

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+)

Step 5: Balance the charges: add electrons to the more positive side (or less negative side).

Step 6: Balance electrons on the two half-reactions.

Step 7: Get the overall reaction by adding the two reactions.

When balancing under basic conditions, additional steps are required:

Step 8: Balance remaining H+ by adding an equal amount of OH ions to both sides.

Step 9: H+(aq) will combine with OH(aq) to form H2O(l).

Step 10: Cancel out common species.

a. H2O2(aq) + ClO2(aq) → ClO2-(aq) +O2(g)

(1-2): Separate and balance non-H and O atoms

H2O2(aq) →  O2(g)

ClO2(aq) → ClO2-(aq)

H2O2(aq) →  O2(g)

ClO2(aq) → ClO2-(aq)

H2O2(aq) →  O2(g) + 2 H(aq)

ClO2(aq) → ClO2-(aq)

(5): Balance charges

H2O2(aq) →  O2(g) + 2 H(aq) + 2 e-

ClO2(aq) + 1 e- → ClO2-(aq)

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Problem Details

Balance each of the following redox reactions occurring in basic solution.

a. H2O2(aq) + ClO2(aq) → ClO2-(aq) +O2(g)

b. Al(s)+MnO4-(aq) → MnO2(s) + Al(OH)4-(aq)

c. Cl2(g) → Cl(aq)+ ClO(aq)