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JEE Main 202522 JanuaryEvening Shift
Exam
JEE Main
Year
2025
Date
22 January
Shift
Evening Shift
Subject
Chemistry
Chapter
Coordination Compounds

JEE Main 2025 · 22 January · Evening Shift · Chemistry · Coordination Compounds

Identify the homoleptic complex(es) that is/are low spin. (A)...

Identify the homoleptic complex(es) that is/are low spin. (A) [Fe(CN)5NO]2−\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{2-} (B) [CoF6]3−\left[\mathrm{CoF}_6\right]^{3-} (C) [Fe(CN)6]4−\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-} (D) [Co(NH3)6]3+\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+} (E) [Cr(H2O)6]2+\quad\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+} Choose the correct answer from the options given below :

Options

  1. A(C) only
  2. B(C) and (D) only
  3. C(A) and (C) only
  4. D(B) and (E) only

Correct answer

B. (C) and (D) only

Step-by-step solution

(A) [Fe(CN)5NO]−2→\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{-2} \rightarrow Heteroleptic, Fe+2,3 d6\mathrm{Fe}^{+2}, 3 \mathrm{~d}^6, t2 g6eg0, d2sp3\mathrm{t}_{2 \mathrm{~g}}{ }^6 \mathrm{e}_{\mathrm{g}}{ }^0, \mathrm{~d}^2 \mathrm{sp}^3, Low spin ( 3 d series +SFL ) (B) [CoF6]−3→\left[\mathrm{CoF}_6\right]^{-3} \rightarrow Homoleptic, sp3 d2\mathrm{sp}^3 \mathrm{~d}^2, High spin, Co+3,3 d6(3 d\mathrm{Co}^{+3}, 3 \mathrm{~d}^6(3 \mathrm{~d} series + WFL )) (C) [Fe(CN)6]−4→\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{-4} \rightarrow Homoleptic Fe+2,3 d6, d2sp3,t2 g6eg0\mathrm{Fe}^{+2}, 3 \mathrm{~d}^6, \mathrm{~d}^2 \mathrm{sp}^3, \mathrm{t}_{2 \mathrm{~g}}{ }^6 \mathrm{eg}^0 Low spin (3 d(3 \mathrm{~d} series +SFL)) (D) [Co(NH3)6]+3→\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{+3} \rightarrow Homoleptic, Co+33 d6, d2sp3\mathrm{Co}^{+3} 3 \mathrm{~d}^6, \mathrm{~d}^2 \mathrm{sp}^3, t2 g6eg0\mathrm{t}_{2 \mathrm{~g}}{ }^6 \mathrm{eg}^0, Low spin (3d series + SFL) (E) [Cr(H2O)6]+2→\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{+2} \rightarrow Homoleptic Cr+23 d4, d2sp3\mathrm{Cr}^{+2} 3 \mathrm{~d}^4, \mathrm{~d}^2 \mathrm{sp}^3, High spin t2 g3eg1\mathrm{t}_{2 \mathrm{~g}}{ }^3 \mathrm{e}_{\mathrm{g}}{ }^1 (3d series + WFL)
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