PUC Karnataka Science Class 12Department of Pre-University Education, Karnataka
It's free!


Create free account

      Forgot password?

View all notifications
Books Shortlist
Your shortlist is empty

Solution - Which is a Stronger Reducing Agent Cr2+ Or Fe2+ And Why? - PUC Karnataka Science Class 12 - Chemistry


Which is a stronger reducing agent Cr2+ or Fe2+ and why?

Solution 1

The following reactions are involved when Cr2+ and Fe2+ act as reducing agents.

`Cr^(2+) -> Cr^(3+)Fe^(2+) -> Fe^(3+)`

The  `E_((Cr^(3+))/(Cr^(2+)))^@` value is -0.14 V and `E_(" "(Fe^(3+))/(Fe^(2+)))^@` is + 0.77 V. This means that Cr2+ can be easily oxidized to Cr3+, but Fe2+ does not get oxidized to Fe3+ easily. Therefore, Cr2+ is a better reducing agent that Fe3+.

Solution 2

Cr2+ is a stronger reducing agent than Fe2+. This is because E°(Cr3+/Cr2+) is negative (- 0.41V) whereas E°(Fe3+/Fe2+) is positive (+ 0.77 V). Thus, Cr2+ is easily oxidised to Fe3+ but Fe2+ cannot be easily oxidised to Fe3+.

Is there an error in this question or solution?


 NCERT Chemistry Textbook for Class 12 Part 1 (with solutions)
Chapter 8: The d-block and f-block Elements
Q: 7 | Page no. 220

Reference Material

Solution for question: Which is a Stronger Reducing Agent Cr2+ Or Fe2+ And Why? concept: null - General Properties of the Transition Elements (D-block). For the courses PUC Karnataka Science, CBSE (Science), CBSE (Arts), CBSE (Commerce)