MHTCET 17 Apr 2026 Shift 2 Paper

Concept:EAN is the total number of electrons around the central metal ion, which is the sum of electrons on the metal and electrons donated by ligands.Explanation:For $\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)_{4}\right]^{2+}$, the atomic number of copper is $Z = 29$.Since $\mathrm{NH}_{3}$ is a neutral ligand, the oxidation state of Cu in this complex is $+2$.So the number of electrons remaining on the $\mathrm{Cu}^{2+}$ ion is $29 - 2 = 27$.Each $\mathrm{NH}_{3}$ ligand donates one lone pair, which contributes 2 electrons.Total electrons donated by 4 ligands $= 4 \times 2 = 8$.Therefore, EAN is calculated as:$$\mathrm{EAN} = (29 - 2) + (4 \times 2) = 27 + 8 = 35$$Answer:The EAN of the metal ion is 35, which corresponds to Option A.