Reactants: 2VCl_2 + 3Cl_2; product: 2VCl_5
Step 1. Pick the most complicated-looking formula (VCl_5) and balance its atoms (V and Cl).
1VCl_2 + (3/2)Cl_2 → 1VCl_5
Oops! Fractional coefficients!
Step 2. Multiply all coefficients by a number (2) to give integer coefficients.
2VCl_2 + 3Cl_2 → 2VCl_5
