Question

Given below are two statements :
Statement I : $[ Ni ( CN ) 4]^{2-}$ is square planar and diamagnetic complex. with $dsp ^{2}$ hybridization for $Ni$ but $\left[ Ni ( CO )_{4}\right]$ is tetrahedral. paramagnetic and with $sp ^{3}$-hybridication for $Ni$.
Statement II: $\left[ NiCl _{4}\right]^{2-}$ and $\left[ Ni ( CO )_{4}\right]$ both have same d-electron configuration have same geometry and are paramagnetic.
In light the above statements. choose the correct answer form the options given below:

• A. Both Statement I and Statement II are true.
• B. Both Statement I and Statement II are false.
• C. Statement I is correct but statement II is false.
• D. Statement I is incorrect but statement II is true

Answer 1

Answer: (B)

$\left[ Ni ( CN )_{4}\right]^{2-}: d ^{8}$ configuration, SFL, sq. planar splitting $\left( dsp ^{2}\right)$, diamagnetic.
$\left[ Ni ( CO )_{4}\right]: d ^{10}$ config (after excitation), SFL, tetrahedral splitting $\left( sp ^{3}\right)$, diamagnetic.
$\left[ NiCl _{4}\right]^{2-}: d ^{8}$ config, WFL, tetrahedral
splitting $\left( sp ^{3}\right)$, paramagnetic(2 unpaired $\left.e ^{-}\right)$.