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Question #44123

Difficulty: 8/10 | 🟢 Free

The Question

A coordination compound has the empirical formula \ce{CoCl3 \cdot 2en} (where \ce{en} = ethane-1,2-diamine). When $0.1\text{ mol}$ of this compound is dissolved in water and treated with excess \ce{AgNO3(aq)} at $298\text{ K}$ , exactly $14.35\text{ g}$ of a white precipitate is formed. The complex cation is known to exhibit optical isomerism. (Given: Molar mass of \ce{AgCl} = $143.5\text{ g/mol}$ )

According to Werner's Coordination Theory, let: $P$ = Primary valency of the central metal atom (magnitude of the oxidation state used in Stock notation). $S$ = Secondary valency of the central metal atom. $N$ = Total number of stereoisomers possible for the complex cation.

Calculate the value of the expression $(P^2 + S^2 + N^2)$ .

Options

A.
54
B.
49
C.
46
D.
29

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Mechanism_Trap

Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.

Concepts Behind This Question

Stock Notation Logic|Werner’s Theory Postulates|Ligand Denticity Variations

Why This Question Is Tricky

Common Mistakes

This problem tests the fundamental postulates of Werner's Coordination Theory and stereochemistry.

It features three distinct traps: (1) Conflating primary valency with the number of ionizable counter-ions (yielding P=1 instead of the oxidation state P=3). (2) Misidentifying the denticity of ethylenediamine as monodentate, leading to an incorrect secondary valency (S=4). (3) Failing to account for the optical activity of the cis-isomer of [M(AA)2a2] complexes, leading to an undercounting of stereoisomers (N=2 instead of N=3).

Only a student who correctly navigates all three concepts will arrive at 54.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Redox Reactions - Class 11 Part 2
Concept	Stock Notation Logic
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free