Account for the
Bi(V) is a stronger oxidising agent than Sb(V).

Explanation

Since, Bi in +5 oxidation state has a tendency to reduce into more stable +3 oxidation state by the acceptance of two electrons and hence acts as a strong oxidising agent.
`Bi^(5+) + 2e^(-) rarr Bi^(3+)`
In contrast, Sb in +5 oxidation state is more stable than its +3 oxidation state. Therefore, Sb (V) has a less tendency to accept a pair of electrons than `Bi^(5+)` Hence, Bi (V) is a stronger oxidising agent than Sb(V).