We need to identify which equation(s) are not balanced. Here are the options:
( \text{SnCl}_4(l) + 2\text{H}_2O(l) \rightarrow \text{SnO}_2(s) + \text{HCl}(aq) )
( 2\text{Al}(s) + 6\text{HCl}(aq) \rightarrow 2\text{AlCl}_3(aq) + 3\text{H}_2(g) )
( C_2H_4(g) + 3O_2(g) \rightarrow 2CO_2(g) + 4H_20(l) )