Question

What is the shape of the cuprammonium ion?

• A. Octahedral
• B. Tetrahedral
• C. Trigonal
• D. Square planar

Answer 1

The correct option is D

Square planar

Explanation for correct option:

D. Square planar

Cuprammonium ion:

• Consider cuprammonium ion complex i.e. ${\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{2+}$.
• ${\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_4\right]}^{2+}$ is a complex of ${\mathrm{ML}}_4$ type. It has an exception is square planar complexes.
• The ammonia molecule is a strong field ligand. The pairing will take place and lead to ${\mathrm{dsp}}^2$ hybridization.
• The hybridization and geometry are discussed below:

Explanation for incorrect options:

$\left[\mathrm{Cu}{{\left({\mathrm{NH}}_3\right)}_4}^{2+}\right]$ has a square planar geometry. Thus, options A, B, and C are incorrect.

Hence, the correct option is D i.e. Square planar.