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Question #44673

Difficulty: 8/10 | 🟢 Free

The Question

A neutral transition metal carbonyl complex of Platinum ( $\ce{Pt}$ , atomic mass $= 195 \text{ u}$ ) is isolated. Elemental analysis yields the following mass composition: $\ce{Pt} = 69.88\%$ , $\ce{C} = 12.91\%$ , $\ce{O} = 17.21\%$ .

Calculate the sum of the atomicity (total number of atoms) of the true molecular formula and the total valence electron count (18-electron rule count) around its central metal atom.

(Assume the complex exists in its simplest stable form consistent with the analytical data and the relativistic d-orbital contraction typical of heavy transition metals).

Options

A.
23
B.
27
C.
32
D.
46

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Exception_Exposure

Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.

Concepts Behind This Question

Empirical vs Molecular Formula|EAN Rule (Sidgwick's Rule)|d-orbital contraction

Why This Question Is Tricky

Common Mistakes

The problem tests the supremacy of analytical empirical data over theoretical heuristics like the 18-electron (EAN) rule.

Students often fall into the trap of altering the molecular formula (e.g., to $\ce{Pt(CO)4}$ or dimerizing to $\ce{Pt2(CO)6}$ ) to force compliance with the 18-electron rule.

The hidden variable is the relativistic d-orbital contraction in heavy transition metals (like Pt), which stabilizes 16-electron configurations by rendering the empty p-orbital energetically inaccessible for further ligand coordination.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Some Basic Concepts of Chemistry - Class 11 Part 1
Concept	Empirical vs Molecular Formula
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free