Question

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

Answer 1

Yes, Al change oxidation number

Step-by-step 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*-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.