JEE Main20264 April 2026Morning ShiftChemistryCoordination CompoundsActual
Match the List-I with List-II List-I Complex ion List-II Calculated spin only magnetic moment (BM) A. [Cr(H₂O)₆]²⁺ I. 3.87 B. [Co(H₂O)₆]²⁺ II. 5.92 C. [Cu(H₂O)₆]²⁺ III. 4.90 D. [Mn(H₂O)₆]²⁺ IV. 1.73 Choose the correct answer from the options given below:
Options
- AA-I, B-III, C-IV, D-II
- BA-II, B-I, C-III, D-IV
- CA-IV, B-II, C-I, D-III
- DA-III, B-I, C-IV, D-II
Correct answer
D. A-III, B-I, C-IV, D-II
Step-by-step solution
The spin-only magnetic moment is given by the formula = n(n+2) BM, where n is the number of unpaired electrons. A. [Cr(H₂O)₆]²⁺ : Chromium is in the +2 oxidation state. The electronic configuration of Cr²⁺ is [Ar] 3d^4 . Since H₂O is a weak field ligand, no pairing occurs. The number of unpaired electrons is n = 4 . = 4(4+2) = 24 4.90 BM. (A III) B. [Co(H₂O)₆]²⁺ : Cobalt is in the +2 oxidation state. The electronic configuration of Co²⁺ is [Ar] 3d^7 . With H₂O as a weak field ligand, the configuration is t_ 2g ^5 e