Question:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): In aqueous solutions Cr2+ \text{Cr}^{2+} is reducing while Mn3+ \text{Mn}^{3+} is oxidising in nature.
Reason (R): Extra stability to half-filled electronic configuration is observed than incompletely filled electronic configuration.
In the light of the above statement, choose the most appropriate answer from the options given below:

Updated On: Nov 27, 2024
  • Both (A) and (R) are true and (R) is the correct explanation of (A)
  • Both (A) and (R) are true but (R) is not the correct explanation of (A)
  • (A) is false but (R) is true
  • (A) is true but (R) is false
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Explanation of Assertion (A):
In aqueous solutions, Cr2+\text{Cr}^{2+} acts as a reducing agent and is oxidised to Cr3+\text{Cr}^{3+}. This is because Cr3+\text{Cr}^{3+} has a stable d3d^3 electronic configuration. Conversely, Mn3+\text{Mn}^{3+} acts as an oxidising agent and is reduced to Mn2+\text{Mn}^{2+}, which has a stable half-filled d5d^5 electronic configuration.
Explanation of Reason (R):
The half-filled electronic configuration provides extra stability due to symmetrical distribution of electrons and exchange energy. This explains why Cr3+\text{Cr}^{3+} and Mn2+\text{Mn}^{2+} are more stable compared to their respective other oxidation states.
Conclusion:
Both Assertion (A) and Reason (R) are true. The reason given (R) correctly explains why Cr2+\text{Cr}^{2+} is reducing and Mn3+\text{Mn}^{3+} is oxidising, as it is related to the stability of the resulting electronic configurations.

Was this answer helpful?
0
0