Table of contents

This is an oxidation-reduction (redox) reaction:

2 Br0 + 2 e- → 2 Br-I (reduction)

Mg0 - 2 e- → MgII (oxidation)

Br2 is an oxidizing agent, Mg is a reducing agent.

Word equation

Magnesium + bromine → magnesium bromide

Input interpretation

Mg + Br2 → MgBr2

Magnesium bromine magnesium bromide

Balanced equation

Balance the chemical equation algebraically:

Mg + Br2 → MgBr2

Add stoichiometric coefficients, c,, to the reactants and products:

c1Mg + c2Br2 → c3MgBr2

Set the number of atoms in the reactants equal to the number of atoms in the products for Mg and Br:

Mg: c1 = c3

Br: 2c2 = 2c3

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set c1 = 1 and solve the system of equations for the remaining coefficients:

c1=1 c2=1

c3 = 1

Substitute the coefficients into the chemical reaction to obtain the balanced equation:


Mg + Br2 → MgBr2