Explanation:
The given reaction equation is as follows.
\(AlCl_{3} + Na \rightarrow NaCl + Al\)
To balance this equation, we multiply Na by 3 on reactant side and NaCl by 3 also.
Thus, the balanced equation is as follows.
\(AlCl_{3} + 3Na \rightarrow 3NaCl + Al\)
The oxidation and reduction reaction will be as follows.
Oxidation: \(3Na \rightarrow 3Na^{+} + 3e^{-}\)
Reduction: \(Al^{3+} + 3e^{-} \rightarrow Al\)
Thus, we can conclude that oxidation state of sodium changes from 0 to +1.