Question

Identify the correct match from the following for coordinate complex (column A) and respective geometry (column B)

Column A Coordination complex	Column B Geometry
(A). \([\text{Ni}(\text{CN})_{4}]^{-2}\)	(I). Trigonal bipyramidal
(B). \([\text{Ag}(\text{NH}_{3})_{2}]^{+}\)	(II). Linear
(C). \([\text{Ni}(\text{Cl})_{4}]^{2-}\)	(III). Tetrahedral
(D). \([\text{Fe}(\text{CO})_{5}]\)	(IV). Square planar

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

Hint:

Find the coordination number and hybridisation of each complex, using ligand field strength for the nickel complexes.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Geometry depends on coordination number, hybridisation and the strength of the ligand.

Step 2: Nickel complexes
In \([\text{Ni}(\text{CN})_{4}]^{2-}\), \(\text{Ni}^{2+}\) (\(d^{8}\)) with strong field \(\text{CN}^{-}\) pairs its electrons and uses \(dsp^{2}\), so it is square planar.
In \([\text{NiCl}_{4}]^{2-}\), the weak field \(\text{Cl}^{-}\) causes no pairing, so \(sp^{3}\) gives a tetrahedral shape.

Step 3: Other complexes
\([\text{Ag}(\text{NH}_{3})_{2}]^{+}\) has coordination number 2 and \(sp\) hybridisation, so it is linear.
\([\text{Fe}(\text{CO})_{5}]\) has coordination number 5 with \(dsp^{3}\) hybridisation, so it is trigonal bipyramidal.

Step 4: Compare the options
The pairs (A)-(IV), (B)-(II), (C)-(III), (D)-(I) match option (B).

Final Answer:
The correct matching is (A)-(IV), (B)-(II), (C)-(III), (D)-(I). \[ \boxed{\text{(B) }\text{(A) - (IV), (B) - (II), (C) - (III), (D) - (I)}} \]