The correct code for stability, of oxidation states for given cations is:
(i) `Pb^(2+) gt Pb^(4+) ,Tl^(+) lt Tl^(3+)`
(ii) `Bi^(3+) lt Sb^(3+) , Sn^(3+) lt Sn^(4+)`
(iii) `Pb^(3+) gt Pb^(4+),Bi^(3+) gt Bi^(3+)`
(iv) `Tl^(3+) lt ln^(3+), Sn^(2+) gt Sn^(4+)`
(v) `Sn^(2+) lt Pb^(2+) , Sn^(4+) gt Pb^(4+)`
(vi) `Sn^(2+) lt Pb^(2+), Sn^(4+) lt Pb^(4+)`

Options

A. (v) and (vi)
B. (i), (iii) and (vi)
C. (iii) and (v)
D. (ii) and (iv)

Answer

C

Explanation

Due to inert effect the stability of lower oxidation state gradually increases while stability of higher oxidation state gradually decreases downn the group in elements of group 13th to 15th. So correct orders are:
(iii) `Pb^(2+) gt Pb^(4+) , Bi^(3+) gt Bi^(5+)`
(iv) `Sn^(2+) lt Pb^(2+), Sn^(4+) gt Pb^(4+)`.