1
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Identify the homoleptic complexes with odd number of $d$ electrons in the central metal :

(A) $\left[\mathrm{FeO}_4\right]^{2-}$

(B) $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{3-}$

(C) $\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NO}\right]^{2-}$

(D) $\left[\mathrm{CoCl}_4\right]^{2-}$

(E) $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_3 \mathrm{~F}_3\right]$

Choose the correct answer from the options given below :

A

(C) and (E) only

B

(A), (B) and (D) only

C

(B) and (D) only

D

(A), (C) and (E) only

2
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The calculated spin-only magnetic moments of $K_3[Fe(OH)_6]$ and $K_4[Fe(OH)_6]$ respectively are :

A

4.90 and 4.90 B.M.

B

4.90 and 5.92 B.M.

C

5.92 and 4.90 B.M.

D

3.87 and 4.90 B.M.

3
JEE Main 2025 (Online) 29th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The correct increasing order of stability of the complexes based on $\Delta_0$ value is :

  1. I. $[\text{Mn}(\text{CN})_6]^{3-}$

  2. II. $[\text{Co}(\text{CN})_6]^{4-}$

  3. III. $[\text{Fe}(\text{CN})_6]^{4-}$

  4. IV. $[\text{Fe}(\text{CN})_6]^{3-}$
A

I < II < IV < III

B

IV < III < II < I

C

III < II < IV < I

D

II < III < I < IV

4
JEE Main 2025 (Online) 29th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Match List - I with List - II.

List - I (Complex) List - II (Hybridisation & Magnetic characters)
(A) [MnBr4]2- (I) d2sp3 & diamagnetic
(B) [FeF6]3- (II) sp3d2 & paramagnetic
(C) [Co(C2O4)3]3- (III) sp3 & diamagnetic
(D) [Ni(CO)4] (IV) sp3 & paramagnetic

Choose the correct answer from the options given below :

A

(A)-(III), (B)-(I), (C)-(I), (D)-(IV)

B

(A)-(III), (B)-(II), (C)-(III), (D)-(IV)

C

(A)-(IV), (B)-(II), (C)-(I), (D)-(III)

D

(A)-(IV), (B)-(I), (C)-(II), (D)-(III)

JEE Main Subjects
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12