Question

Match the LIST-I with LIST-II

Choose the correct answer from the options given below:

• A. A-I, B-II, C-III, D-IV
• B. A-III, B-II, C-I, D-IV
• C. A-III, B-IV, C-II, D-I
• D. A-IV, B-I, C-III, D-II

Hint:

- Strong field ligands (CO, CN⁻) cause pairing → low spin complexes - Weak field ligands (Cl⁻, Br⁻) don't cause pairing → high spin complexes - Magnetic moment (μ) = √[n(n+2)] BM, where n = unpaired electrons - Ni²⁺ (d⁸): tetrahedral/square planar; Mn²⁺ (d⁵): always high spin

Answer 1

The Correct Option is B

To solve this matching question, we need to understand the relationship between the chemical complexes in LIST-I and their respective shapes and magnetic moments in LIST-II. Here’s the explanation for each:

1. [Ni(CO)₄]: Carbon monoxide (CO) is a strong field ligand, leading to the pairing of electrons in the nickel atom. This complex is tetrahedral and diamagnetic (0 BM). 
   Matches with III: Tetrahedral, 0 BM.
2. [Ni(CN)₄]²⁻: Cyanide (CN) is another strong field ligand, causing electron pairing. The complex is square planar and diamagnetic. 
   Matches with II: Square planar, 0 BM.
3. [NiCl₄]²⁻: Chloride (Cl) is a weak field ligand, resulting in unpaired electrons in the nickel atom. This complex is tetrahedral with a magnetic moment. 
   Matches with I: Tetrahedral, 2.8 BM.
4. [MnBr₄]²⁻: Bromide (Br) is also a weak field ligand, leading to unpaired electrons in manganese. This complex is tetrahedral with a magnetic moment. 
   Matches with IV: Tetrahedral, 5.9 BM.

Based on the above analysis, the correct matching is:

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

Thus, the correct answer is:

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

This matches the provided correct answer option, ensuring the pairing between complexes and their corresponding properties is accurately justified.

Answer 2

To solve the question, we need to match each complex or species in LIST-I with its corresponding shape and magnetic moment given in LIST-II. Let’s analyze each option in LIST-I:

1. [Ni(CO)₄]
   • In [Ni(CO)₄], Ni is in the zero oxidation state. CO is a strong field ligand and causes pairing of electrons, leading to a tetrahedral geometry with 0 BM magnetic moment since there are no unpaired electrons.
   • Correct match: III. Tetrahedral, 0 BM
2. [Ni(CN)₄]^2–
   • In this complex, CN⁻ is a strong field ligand, which leads to the pairing of electrons in the d-orbitals. This results in a square planar geometry with 0 BM magnetic moment as there are no unpaired electrons.
   • Correct match: II. Square planar, 0 BM
3. [NiCl₄]^2–
   • Here, Cl⁻ is a weak field ligand, so it does not cause pairing of electrons. This results in a tetrahedral geometry with a magnetic moment of 2.8 BM due to unpaired electrons.
   • Correct match: I. Tetrahedral, 2.8 BM
4. [MnBr₄]^2–
   • For this complex, with Mn in a high spin state due to weak field Br⁻ ligands, it adopts a tetrahedral geometry with a significant magnetic moment of 5.9 BM due to the presence of unpaired electrons.
   • Correct match: IV. Tetrahedral, 5.9 BM

Thus, the correct matching is A-III, B-II, C-I, D-IV.

Therefore, the correct option is:

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