JEE Main20241 Feb 2024Evening ShiftChemistryd and f Block ElementsActual
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R . Assertion A : In aqueous solutions Cr 2 + is reducing while 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
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
- CA is false but R is true
- DA is true but R is false
Correct answer
A. Both A and R are true and R is the correct explanation of A
Step-by-step solution
A reducing agent, or reductant, loses electrons and is oxidized in a chemical reaction. A reducing agent is typically in one of its lower possible oxidation states, and is known as the electron donor. Cr 2 + is reducing as it configuration changes from d 4 to d 3 due to formation of Cr 3 + , which has half filled t 2 g level, on other hand, the change Mn 3 + to Mn 2 + result half filled d 5 configuration which has extra stability.