How many of the following ligands are stronger than $\mathrm{H}_2 \mathrm{O}$ ? $\mathrm{S}^{2-},…
How many of the following ligands are stronger than $\mathrm{H}_2 \mathrm{O}$ ? $\mathrm{S}^{2-}, \mathrm{Br}^{-}, \mathrm{C}_2 \mathrm{O}_3^{2-}, \mathrm{CN}^{-}$, en, $\mathrm{NH}_3, \mathrm{CO}, \mathrm{OH}^{-}$
5
3
4
6
Solution
The ligands are classified as weak and strong ligand. According to spectrochemical series.
$\begin{aligned}
& \mathrm{I}^{-} \lt \mathrm{Br}^{-} \lt \mathrm{S}^{2-} \lt \mathrm{SCN}^{-} \lt \mathrm{Cl}^{-} \lt \mathrm{N}_3^{-} \lt \mathrm{F}^{-} \lt \text {urea } \lt \mathrm{OH}^{-} \\
& \lt \mathrm{C}_2 \mathrm{H}_5 \mathrm{OH} \lt \mathrm{C}_2 \mathrm{O}_4^{-} \lt \mathrm{O}^{2-} \lt \mathrm{H}_2 \mathrm{O} \lt \mathrm{NCS}^{-} \lt \mathrm{gly} \lt \mathrm{NH}_3 \lt \text { en } \\
& \lt \mathrm{NH}_2 \mathrm{OH} \lt \mathrm{bPy} \lt \mathrm{NO} \lt \mathrm{CH}_3^{-} \lt \mathrm{C}_6 \mathrm{H}_5^{-} \lt \mathrm{CN}^{-} \lt \mathrm{CO}
\end{aligned}$
$\therefore 4$ ligands are strong then $\mathrm{H}_2 \mathrm{O}$