Question

state the valency of sulphur in so2 and so3

Answer 1

In $SO_{2}$, the valency of sulphur is 4. 
In $SO_{3}$, the valency of sulphur is 6. 

Hope this may help you. 

Answer 2

Explanation:

We can determine the valency by the number of oxygen atoms present in $SO_2$ and $SO_3$.

As we can observe that in $SO_2$, number of oxygen atoms is -2 and the valency of oxygen atom is 2.

Thus, the total valency become -4.

Therefore, the valency of S will be +4. Likewise, in the $SO_3$, the number of oxygen atoms is 3.

Thus, that gives us a valency of +6 on the sulphur.