Chapter 19, Problem 65A

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 65A

Oxidation half reaction:

$C_2{O}_4{}^{2-}\to 2C{O}_2+2e^{-}$

Reduction half reaction:

$As{O}_2{}^{-}+4H^{+}+3e^{-}\to As+2H_{2}O$

Explanation of Solution

The given reaction is:

$3H_2{C}_2{O}_4+2HAs{O}_2\to 6C{O}_2+2As+4H_{2}O$

Equation in ionic form is:

$C_2{O}_4{}^{2-}+As{O}_2{}^{-}\to C{O}_2+2As$

Thus half reactions are:

Oxidation half reaction:

$C_2{O}_4{}^{2-}\to 2C{O}_2+2e^{-}$

Reduction half reaction:

$As{O}_2{}^{-}+4H^{+}+3e^{-}\to As+2H_{2}O$

Conclusion

Thus,

Oxidation half reaction:

$C_2{O}_4{}^{2-}\to 2C{O}_2+2e^{-}$

Reduction half reaction:

$As{O}_2{}^{-}+4H^{+}+3e^{-}\to As+2H_{2}O$