In view of the signs of `Delta_rG^@` for the following reactions
`PbO_2 + Pb to 2PbO, Delta_r G^@ lt 0`
`SnO_2 +Sn to 2SnO, Delta_rG^@ gt 0`
Which oxidation states are more characteristic for lead and tin?

Options

A. For lead +4, for tin +2
B. for lead +2, for lin +2
C. for lead +4, for tin +4
D. for lead +2, for tin +4

Answer

D

Explanation

`underset(+4)(PbO_(2)) + underset(0)(PB) to underset(+2)(PbO`
Since, `Delta_(r)G^(@) lt 0`, hence +2 states of lead is favourable
`underset(+4)(SnO_(2)) + underset(0)(Sn) to underset(+2)(2SnO)`
Since, `Delta_(r)G^(@)O gt 0`, it means forward reaction is not spontaneous
`underset(+2)(2SnO) to underset(+9)(SnO_(2)) +underset(0)(Sn)`
For this, `Delta_(r)G^(@) lt 0` thus, `+4` state of tin is favourable