Question

With reference to protonic acids, which of the following statements is correct?

• A. $P{H}_3$ is more basic than $N{H}_3$
• B. $P{H}_3$ is less basic than $N{H}_3$
• C. $P{H}_3$ is equally basic than $N{H}_3$
• D. $P{H}_3$ is amphoteric while $N{H}_3$ is basic
• E. None of the above

Answer 1

The correct option is B $P{H}_3$ is less basic than $N{H}_3$

$P{H}_3$ is less basic than $N{H}_3$. The hydrides of group 15 are basic in character due to the presence of lone pair of electrons. Ammonia is strongly is basic because it can easily donate its electron pair. due to the small size of nitrogen atom. Since the electron density of lone pair is concentrated over a small region in nitrogen, $N{H}_3$ can easily attract proton in aqueous solution. $P{H}_3$ is weakly basic because of large size of $P$. the electron density around $P$ gets diffused over a lare region and ability to attract proton decreases.