Balance the half equation for the formation of aluminium during electrolysis: Al 3+ + e-→ Al. The balanced half equation is: Al 3+ + 3e-→ Al (because three negatively charged electrons are needed to ...

If the words shown above are replaced by the correct chemical formulae, it will result in an unbalanced equation, as shown here. Cu + O 2 → CuO Notice that there are unequal numbers of each type of ...