Chapter 19.1, Problem 1PPA

Interpretation Introduction

Interpretation:

The given equation is to be balanced in the basic medium by the half-reaction method.

Concept introduction:

In the half-reaction method of balancingachemical reaction, the redox reaction is written in two halves. One is the oxidation half-reaction and the other is the reduction half-reaction. Then, each of these half-reactions arebalanced separately, and then combined to give the balanced redox equation.

The following are the steps to balance the chemical equation in the basic medium:

Step 1: Write the skeleton equationin ionic form.

Step 2: Separate the unbalanced reaction into half reactions.

Step 3: Balance the number of oxidized and reduced atomsso that both the sides have the same oxidation state. This is done by adding electrons to the more positive side to make it equal to the less positive side of the half-reaction.

Step 4: Balance the charge so that both sides have the same total charge by adding an OH^- ion to the side deficient in the negative charge.

Step 5: Balance the oxygen atoms by adding ${\text{H}}_{\text{2}}\text{O}$ to the deficient side in the half reactions.

Step 6: Make the electron gain equivalent to the electron loss in the oxidation half reactions and reduction half reactions.

Step 7: Combine the two half reactions together.

Step 8: Remove chemical species of asimilar kind, if any, and write the simplified chemical equation.