Question

AICI, + NaNaCl + Al Did Al change oxidation number? yes No

Answer 1

Answer:

Yes, Al change oxidation number

Explanation:

$AlCl_3 +Na >NaCl+Al$

For a free element, oxidation number is 0.

Na and Al are free elements we find in the equation as they are not in combination with other elements.

For a compound, the sum of oxidation number of elements = 0.

We know oxidation number of chlorine is -1.

So let us find the oxidation number of Al in $AlCl_3$

Let x be the oxidation number of Al so,

$AlCl_3=x+(3\times-1)=0\\\\x-3=0\\\\ x= +3$

Oxidation number of Al in $AlCl_3$  is +3

Oxidation number of Al  changes from +3 to 0.

Decrease in oxidation number indicates $AlCl_3$ is getting reduced in the reaction.

Na oxidation number increases from 0 to +1 shows Na is getting oxidised in the reaction  

The change in oxidation number of the elements represents a redox reaction where both oxidation and reduction takes place simultaneously.