Question

When `ZnS` is boiled with strong nitric acid, the products are zinc nitrate, sulphuric acid and nitrogen dioxide. What are the changes in the oxidation numbers of `Zn`, `S` and `N`?
A. `+2`, `+4`, `-1`
B. `+2`, `+6`, `-2`
C. `0`, `+4`, `-2`
D. `0`, `+8`, `-1`

Answer 1

Correct Answer - D
`overset(+2)(Zn)overset(-2)(S)+overset(+5)(HNO) rarr overset(+2)(Zn)overset(-5)((NO_(3)))_(2)+H_(2)overset(+6)(SO_(4))+overset(+4)(NO_(2))`
Change in `O.N.` of `Zn`
`Zn=0`
`S=6-(-2)=8`
`N=5-4=1`