NEETChemistryd and f Block Elements
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Cu 2 + in water is more stable than Cu + . Reason (R) : Enthalpy of hydration for Cu 2 + is much less than that of Cu + . In the light of the above statements, choose the correct answer from the options given below :
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A).
- B(A) is correct but (R) is not correct.
- C(A) is not correct but (R) is correct.
- DBoth (A) and (R) are correct but (R) is not the correct explanation of (A).
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
Step-by-step solution
2 Cu + → Cu 2 + + Cu The stability of Cu 2 + ( aq ) rather than Cu + ( aq ) , is due to the much more negative ∆ hyd H of Cu 2 + ( aq ) than Cu + ( aq ) , which more than compensates for the second ionisation enthalpy of Cu . Hence, both (A) and (R) are correct and (R) is the correct explanation of (A).