In view of the signs of `Delta_(r)G^(0)` for the following reactions
`PbO_(2)+Pbrarr2PbO,Delta_(r)G^(0)lt0`
`SnO_(2)+Snrarr2SnO,Delta_(r)G^(0)gt0`
Which oxidation state are more characteristic for lead and tin?

Options

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

Answer

d

Explanation

`overset(+4)(PbO_(2))+Pb rarr overset(+2)(2PbO) `. As`Delta_(r)G^(@) lt 0`, i.e., it isnegative , thereaction is spontanoeus in the forward direction, i.e., `Pb^(+2)` is more stable than`Pb^(+4)`
`overset(+4)(SnO_(2)) +Sn rarr overset(+2)(2SnO)`. As `Delta_(r)G^(@) gt 0`, i.e., it is positive,reverse reaction will be spotaneous , i.e., `Sn^(+4)` will be more stable than`Sn^(+2)`. These facts are also supported by the inert pair effect down the group.