Chapter 8.2, Problem 6RQ

Interpretation Introduction

Interpretation:

The gain and loss of electrons in the magnesium nitride production from Mg and N₂ must be shown.

Concept Introduction:

The reaction of Mg and N₂ is a redox reaction in which Mg is oxidized and N is reduced.

Answer to Problem 6RQ

2Mg has lost total 6 electrons which are accepted by 2 N.

Explanation of Solution

Electron gain and loss is shown below.

  $\begin{array}{l}\text{3Mg(s)}\to {\text{3Mg}}^{\text{2+}}{\text{+6e}}^{-}\\ {\text{N}}_{\text{2}}{\text{(g)+6e}}^{-}\to {\text{2N}}^{\text{3-}}\end{array}$

In this reaction, each Mg loses $2e^{-}$ . So total electron loss by Mg are 6.

Each N gains $3e^{-}$ . So, the total electrons gained by 2 N is 6.