Question

Which one of the following pentafluoride cannot be formed?

• A. $P{F}_5$
• B. $As{F}_5$
• C. $Sb{F}_5$
• D. $Bi{F}_5$

Answer 1

Answer: (D)

Bismuth due to inert pair effect exists with only $+3$ oxidation state. $+5$ oxidation state is uncommon for $Bi$. So, bismuth does not form pentahalide.