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): Ce ⁴⁺ is widely used as a good analytical reagent in aqueous medium. Reason (R): The oxidation of water by Ce ⁴⁺ is kinetically very slow. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DAssertion (A) is false but Reason (R) is true.
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true: Ce ⁴⁺ is widely used as a good analytical reagent in aqueous solutions. Reason (R) is true and explains Assertion (A): The standard electrode potential for the Ce ⁴⁺/ Ce ³⁺ couple is +1.74 V , which indicates that thermodynamically it can oxidise water. However, the reaction rate is kinetically very slow. Because this oxidation of water is so slow, aqueous solutions of Ce ⁴⁺ are sufficiently stable to be used as analytical reagents. Thus, both (A) and (R) are true and (R) is the correct expla