Question

Assertion : $NF_3$ is a weaker ligand than $N(CH_3)_3$.
Reason : $NF_3$ ionizes to give $F^-$ ions in aqueous solution.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (C)

Due to high electronegativity and electron withdrawing nature of $F$-atom, the lone pair of $N$ -atom in $NF _{3}$ molecule is not easily available for donation. Whereas in $N \left( CH _{3}\right)_{3},-$ $CH _{3}$ group is an electron releasing group, thus lone pair of N-atom in $N \left( CH _{3}\right)_{3}$ molecule can be ligated easily. Except, nitrogen fluoride, all other trihalides hydrolyse in water.

$NCl _{3}+3 H _{2} O \longrightarrow NH _{3}+3 HOCl$