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JEE Main 20244 AprilMorning Shift
Exam
JEE Main
Year
2024
Date
4 April
Shift
Morning Shift
Subject
Chemistry
Chapter
Coordination Compounds

JEE Main 2024 · 4 April · Morning Shift · Chemistry · Coordination Compounds

Number of complexes from the following with even number of unpaired...

Number of complexes from the following with even number of unpaired " (\mathrm{d}) " electrons is (\qquad) (\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}) [Given atomic numbers : (\mathrm{V}=23, \mathrm{Cr}=24, \mathrm{Fe}=26, \mathrm{Ni}=28 \mathrm{Cu}=29)]

Options

  1. A2
  2. B1
  3. C4
  4. D5

Correct answer

A. 2

Step-by-step solution

[V(H2O)6]3+→d2sp323V:−[Ar]3d34s2V+3:−[Ar]3d2,n=2 (even number of  unpaired e−)[Cr(H2O)6]2+→sp3d224Cr:−[Ar]3d54s1Cr+2:−[Ar]3d4,n=4 (even number of unpaired e−)\begin{aligned} & {\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+} \rightarrow \mathrm{d}^2 \mathrm{sp}^3} \\ & { }_{23} \mathrm{ V}:-[\mathrm{Ar}] 3 \mathrm{ d}^3 4 \mathrm{ s}^2 \\ & \left.\mathrm{ V}^{+3}:-[\mathrm{Ar}] 3 \mathrm{ d}^2, \mathrm{n}=2 \text{ (even number\text{ of } unpaired } \mathrm{e}^{-}\right) \\ & {\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \rightarrow \mathrm{sp}^3 \mathrm{ d}^2} \\ & { }_{24} \mathrm{Cr}:-[\mathrm{Ar}] 3 \mathrm{ d}^5 4 \mathrm{ s}^1 \\ & \left.\mathrm{Cr}^{+2}:-[\mathrm{Ar}] 3 \mathrm{ d}^4, \mathrm{n}=4 \text{ (even number of unpaired } \mathrm{e}^{-}\right)\end{aligned}[Fe(H2O)6]3+→sp3d2Fe3+:−[Ar]3d54s0n=5( odd number of unpaired e−)[Ni(H2O)6]3+→sp3d2Ni:−[Ar]3d84s2Ni+3:−[Ar]3d7,n=3 (odd number of unpaired e−)[Cu(H2O)6]2+→sp3d2Cu:−[Ar]3d94s0n=1 (odd number of unpaired e−)\begin{aligned} & {\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+} \rightarrow \mathrm{sp}^3 \mathrm{ d}^2} \\ & \mathrm{Fe}^{3+}:-[\mathrm{Ar}] 3 \mathrm{ d}^5 4 \mathrm{ s}^0 \\ & \mathrm{n}=5\left(\text{ odd number of unpaired } \mathrm{e}^{-}\right) \\ & {\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+} \rightarrow \mathrm{sp}^3 \mathrm{ d}^2} \\ & \mathrm{Ni}:-[\mathrm{Ar}] 3 \mathrm{ d}^8 4 \mathrm{ s}^2 \\ & \left.\mathrm{Ni}^{+3}:-[\mathrm{Ar}] 3 \mathrm{ d}^7, \mathrm{n}=3 \text{ (odd number of unpaired } \mathrm{e}^{-}\right) \\ & {\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} \rightarrow \mathrm{sp}^3 \mathrm{ d}^2} \\ & \mathrm{Cu}:-[\mathrm{Ar}] 3 \mathrm{ d}^9 4 \mathrm{ s}^0 \\ & \left.\mathrm{n}=1 \text{ (odd number of unpaired } \mathrm{e}^{-}\right)\end{aligned}$
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