When balancing a redox reaction, begin by separating the reaction into . Balance each of these in terms of .
Multiply by some factor if necessary so that the number of appearing in both is the same. Add these together, canceling out any terms that appear on both sides of the final equation.
Provide the coefficients needed to balance the redox reaction given.
2 - Fe(s) + 3 C l2(g) 2 Fe3+ (aq) + 6 - Cl(aq)