AIPMT PRELIMS2000Chemistry-Coordination Compounds
AIPMT PRELIMS 2000 Chemistry Stability of Complexes MCQ Question
Type: MCQ-conceptual-Hard-Class 12
In quantitative analysis of second group in lab. H₂S gas is passed in acidic medium for ppt. When Cu²⁺ and Cd²⁺ react with KCN, than in which of the following condition, ppt will not be formed due to relative stability :
A
K₁[Cu(CN)₄] – More stable K₂[Cd(CN)₄] – Less stable
B
K₂[Cu(CN)₄] – Less stable K₁[Cd(CN)₄] – More stable
C
K₃[Cu(CN)₄] – More stable K₂[Cd(CN)₄] – Less stable
D
K₅[Cu(CN)₄] – More stable K₃[Cd(CN)₄] – Less stable
Correct Answer
Option C
Detailed Explanation
Precipitation will not occur if the complex formed is more stable. Here, K₁[Cu(CN)₄] is more stable than K₂[Cd(CN)₄], preventing precipitation.
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