Question

Which o f the following facts about the complex $[Cr(NH_{3})_{6}]Cl_{3}$ is wrong?

• A. The complex involves $d^{2} sp^{3}$ hybridization and is octahedral in shape
• B. The complex is paramagnetic
• C. The complex is an outer orbital complex
• D. The complex gives white precipitate with silver nitrate solution.

Answer 1

Answer: (C)

In $[Cr(NH_{3})_{6}]^{3+}$, $Cr$ exists as $Cr^{3+}$ ion. The outer orbital electronic configuration of $Cr$ is $3d^{3} 4S^{0}$. The orbital diagram is represented by

Here, X indicates lone pair of $NH_{3}$ donated to Cr. Hence,
(a) $d^{2}-sp^{3}$ hybridization, octahedral. Thus, correct.
(b) There are three unpaired electrons, hence paramagnetic. Thus, correct.
(c) $d^{2}-sp^{3}$ inner orbital complex, thus incorrect.
(d) Due to ionizable $Cl^-$ ions, white precipitate with $AgNO_{3}$, thus correct.