This is an oxidation-reduction (redox) reaction:
2 Br-I - 2 e- → 2 Br0 (oxidation)
CuII + 2 e- → Cu0 (reduction)
CuBr2 is a reducing agent, CuBr2 is an oxidizing agent.
Word equation
cupric bromide → copper + bromine
Input interpretation
CuBr2 → Cu + Br2
cupric bromide copper bromine
Balanced equation
Balance the chemical equation algebraically:
CuBr2 → Cu + Br2
Add stoichiometric coefficients, c, to the reactants and products:
c1 CuBr2 → c2Cu + c3Br2
Set the number of atoms in the reactants equal to the number of atoms in the products for Br and Cu:
Br: 2c1 = 2c3
Cu: c1=c2
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:
CuBr2 → Cu + Br2