Question

Which of the following is the weakest reducing agent in group 15?

Options

• \[\ce{NH3}\]

• \[\ce{PH3}\]

• \[\ce{AsH3}\]

• \[\ce{BiH3}\]

Answer 1

\[\ce{NH3}\]

Explanation:

In group 15, the reducing power of hydrides (\[\ce{EH3}\]) increases down the group due to a decrease in the bond dissociation energy of the \[\ce{E-H}\] bond. Since \[\ce{NH3}\] has the strongest \[\ce{N-H}\] bond, it is the weakest reducing agent compared to \[\ce{PH3}\], \[\ce{AsH3}\], and \[\ce{BiH3}\].