Question

Standard electrode potentials of redox couples $A ^{2+} / A$ $B ^{2+} / B , C ^{2+} / C$ and $D ^{2+} / D$ are $0.3 \,V ,-0.5 \,V ,-0.75 \,V$ and $0.9 \,V$ respectively. Which of these is best oxidising agent and reducing agent respectively?

• A. $D^{2+} / D$ and $B^{2+} / B$
• B. $B ^{2+} / B$ and $D ^{2+} / D$
• C. $D ^{2+} / D$ and $C ^{2+} / C$
• D. $C^{2+} / C$ and $D^{2+} / D$

Answer 1

Answer: (C)

The redox couple with maximum reduction potential will be best oxidising agent and with minimum reduction potential will be best reducing agent.