Answer : There is no change takes place in the oxidation number of Cl.
Explanation :
The given chemical reaction is,
![AlCl_3+Na\rightarrow NaCl+Al](https://tex.z-dn.net/?f=AlCl_3%2BNa%5Crightarrow%20NaCl%2BAl)
This reaction is an unbalanced reaction because the chlorine atoms are not balanced.
In order to balance the chemical reaction, the coefficient 3 is put before the Na and NaCl.
The balanced chemical reaction will be,
![AlCl_3+3Na\rightarrow 3NaCl+Al](https://tex.z-dn.net/?f=AlCl_3%2B3Na%5Crightarrow%203NaCl%2BAl)
Now we have to calculate the oxidation number of all the elements.
In
, the oxidation number of Al and Cl are, (+3) and (-1) respectively.
The oxidation number Na and Al are, zero (0)
In
, the oxidation number of Na and Cl are, (+1) and (-1) respectively.
From this we conclude that the oxidation number of Cl changes from (-1) to (-1) that means remains same.
Therefore, there is no change takes place in the oxidation number of Cl.