Chapter 19, Problem 71A

(a)

Interpretation Introduction

Interpretation:

The two half reactions of given balanced redox reaction is to be written.

Concept introduction:

Redox reaction is the combination of oxidation and reduction.

Oxidation half reaction represents oxidation and reduction half reaction represents reduction.

Answer to Problem 71A

Oxidation half reaction:

$2N{H}_3\to N_2+6e^{-}+6H^{+}$

Reduction half reaction:

$P{b}^{2+}+2e^{-}\to Pb$

Explanation of Solution

The given reaction is:

$PbO+N{H}_3\to N_2+Pb+H_{2}O$

Equation in ionic form is:

$P{b}^{2+}+N{H}_3\to N_2+Pb$

Thus half reactions are:

Oxidation half reaction:

$2N{H}_3\to N_2+6e^{-}+6H^{+}$

Reduction half reaction:

$P{b}^{2+}+2e^{-}\to Pb$

(b)

Interpretation Introduction

Interpretation:

The two half reactions of given balanced redox reaction is to be written.

Concept introduction:

Redox reaction is the combination of oxidation and reduction.

Oxidation half reaction represents oxidation and reduction half reaction represents reduction.

Answer to Problem 71A

Oxidation half reaction:

$S_2{O}_3{}^{2-}\to S_2{O}_4{}^{2-}+2e^{-}$

Reduction half reaction:

$I_2+2e^{-}\to 2I^{-}$

Explanation of Solution

The given reaction in ionic form is:

$I_2+S_2{O}_3{}^{2-}\to S_2{O}_4{}^{2-}+I^{-}$

Thus half reactions are:

Oxidation half reaction:

$S_2{O}_3{}^{2-}\to S_2{O}_4{}^{2-}+2e^{-}$

Reduction half reaction:

$I_2+2e^{-}\to 2I^{-}$

(c)

Interpretation Introduction

Interpretation:

The two half reactions of given balanced redox reaction is to be written.

Concept introduction:

Redox reaction is the combination of oxidation and reduction.

Oxidation half reaction represents oxidation and reduction half reaction represents reduction.

Answer to Problem 71A

Thus half reactions are:

Oxidation half reaction:

$Sn\to S{n}^{+2}+2e^{-}$

Reduction half reaction:

$2H^{+}+2e^{-}\to H_2$

Explanation of Solution

The given reaction is:

$Sn+2HCl\to SnC{l}_2+H_2$

Equation in ionic form is:

$Sn+2H^{+}\to S{n}^{+2}+H_2$

Thus half reactions are:

Oxidation half reaction:

$Sn\to S{n}^{+2}+2e^{-}$

Reduction half reaction:

$2H^{+}+2e^{-}\to H_2$