Assertion: NF_3 is a weaker ligand than N(CH_3)_3 . Reason : NF_3...

Due to high electronegativity and electron withdrawing nature of $\mathrm{F}$-atom, the lone pair of $\mathrm{N}$-atom in $\mathrm{NF}_3$ molecule is not easily available for donation. Whereas in $\mathrm{N}\left(\mathrm{CH}_3\right)_3,-\mathrm{CH}_3$ group is an electron releasing group, thus lone pair of $\mathrm{N}$-atom in $\mathrm{N}\left(\mathrm{CH}_3\right)_3$ molecule can be ligated easily. Except, nitrogen fluoride, all other trihalides hydrolyse in water. \mathrm{NCl}}_{3}+3 \mathrm{H}}_{2} \mathrm{O} \rightarrow \mathrm{NH}}_{3}+3 \mathrm{HOCl}