NEETChemistryPractical Chemistry
Assertion (A) Cu ²⁺ and Cd ²⁺ are separated by first adding KCN solution and then passing H ₂ ~S gas. Reason (R) KCN reduces Cu ²⁺ to Cu ⁺ and forms a complex with it. The correct answer is
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is not true
- D(A) is not true but (R) is true
Correct answer
B. Both (A) and (R) are true but (R) is not the correct explanation of (A)
Step-by-step solution
KCN forms complex with Cu ⁺ and Cd ²⁺ as K ₃ [ Cu ( CN )₄ ] and K ₂ [ Cd ( CN )₄ ] respectively. On passing H ₂ ~S , only Cd ²⁺ complex gets decomposed to yellow CDS.