JEE Main 2025 — 2 April, Evening Shift — Question 21

$\mathrm{K}_{2}\left[\mathrm{NiCl}_{4}\right] \Rightarrow \mathrm{Ni}^{2+} \Rightarrow 3 \mathrm{~d}^{8} \Rightarrow \mathrm{sp}^{3} \Rightarrow$ Paramagnetic

$\left[\mathrm{Zn}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right] \mathrm{Cl}_{2} \Rightarrow \mathrm{Zn}^{2+} \Rightarrow 3 \mathrm{~d}^{10} \Rightarrow$ diamagnetic

$\mathrm{K}_{3}\left[\mathrm{Mn}(\mathrm{CN})_{6}\right] \Rightarrow \mathrm{Mn}^{3+} \Rightarrow 3 \mathrm{~d}^{4} \Rightarrow$ paramagnetic

$\left[\mathrm{Cu}\left(\mathrm{PPh}_{3}\right) \mathrm{I}\right) \Rightarrow \mathrm{Cu}^{+1} \Rightarrow 3 \mathrm{~d}^{10} \Rightarrow$ diamagnetic

$\mathrm{n}=2$

Zn has least enthalpy of atomisation

$\mathrm{Zn}^{2+} \Rightarrow \mu=0$