[Ni(PPh$_3$)$_2$Cl$_2$] is a paramagnetic complex. Identify the {INCORRECT statements about this complex. A. The complex exhibits geometrical isomerism.
B. The complex is white in colour.
C. The calculated spin-only magnetic moment of the complex is $2.84$ BM.
D. The calculated CFSE (Crystal Field Stabilization Energy) of Ni in this complex is $-0.8\Delta_o$.
E. The geometrical arrangement of ligands in this complex is similar to that in Ni(CO)$_4$.
Choose the correct answer from the options given below:

Question

5.33 gram of $CrCl_3 \cdot 6H_2O$ (1:3 electrolyte) is passed through cation exchanger. The resulting solution is then treated with an excess of $AgNO_3$, leading to formation of 8.61 gran of precipitate. Calculate :
$\frac{\text{number of moles of complex reacted}}{\text{number of moles of AgCl precipitated}} \times 100$

Answer 1

To determine the incorrect statements about the complex $[Ni(PPh_3)_2Cl_2]$, let's analyze each statement one by one:

Statement A: "The complex exhibits geometrical isomerism."
- The coordination complex $[Ni(PPh_3)_2Cl_2]$ has a square planar geometry. Square planar complexes with formula $[\text{ML}_2\text{X}_2]$, where two different types of ligands are present, typically exhibit geometrical isomerism (cis and trans forms).
- Hence, Statement A is correct.
Statement B: "The complex is white in color."
- The color of a complex depends on the ligands and the metal's oxidation state. Square planar Ni(II) complexes are often not intensely colored but can show pale colors depending on ligands.
- However, generally, this complex is expected to have a color due to d-d transitions, and not be completely white.
- Thus, Statement B is incorrect.
Statement C: "The calculated spin-only magnetic moment of the complex is $2.84$ BM."
- Nickel in this complex is in the +2 oxidation state and has a $d^8$ configuration.
- For a square planar configuration, all electrons are paired, making it diamagnetic.
- A spin-only magnetic moment of zero would be expected for diamagnetic substances.
- Therefore, Statement C is incorrect.
Statement D: "The calculated CFSE (Crystal Field Stabilization Energy) of Ni in this complex is $-0.8\Delta_o$ ."
- CFSE for a square planar $d^8$ metal ion is calculated based on splitting patterns different from octahedral complexes ($\Delta_o$).
- Typically calculated CFSE for such Ni(II) complexes do not equate to $-0.8\Delta_o$ as the energy levels and stabilization differ.
- Therefore, Statement D is incorrect.
Statement E: "The geometrical arrangement of ligands in this complex is similar to that in Ni(CO)$_4$.
- $[Ni(CO)_4]$ is a tetrahedral complex, while $[Ni(PPh_3)_2Cl_2]$ is square planar.
- Hence, the geometrical arrangements differ.
- Therefore, Statement E is incorrect.

After evaluating all statements, the incorrect ones are A and B.

Correct Answer: A and B only

Column-I (Complex compound)	Column-II ($\Delta_0$ (CFSE) $\text{cm}^{-1}$)
(i) $[Cr(CN)_6]^{3-}$	(P) 17000
(ii) $[Cr(H_2O)_6]^{3+}$	(Q) 15000
(iii) $[Cr(en)_3]^{3+}$	(R) 12000
(iv) $[CrF_6]^{3-}$	(S) 20000

Show Hint

The Correct Option is B

Solution and Explanation

Top Questions on coordination compounds

Questions Asked in JEE Main exam