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:
Answer:
Mg + Br2 → MgBr2