NTA Abhyas JEE Main2020ChemistryRedox ReactionsPractice
The electrode potential, E ° , for the reduction of M n O 4 - to M n 2 + in acidic medium is +1.51 V. Which of the following metal(s) will be oxidised? The reduction reactions and standard electrode potentials for Z n 2 + , A g + and A u + are given as Z n a q 2 + + 2 e - → Z n s , E ° = - 0.762 V A g a q + + e - ⇌ A g x , E ° = + 0.80 V A u a q + + e - ⇌ A u s , E ° = + 1.69 V
Options
- AZn and Au
- BAg and Au
- CAu
- DZn and Ag
Correct answer
D. Zn and Ag
Step-by-step solution
More +ve the value of reduction potential more will be the tendency to undergo reduction. The E red o MnO 4 − | Mn 2 + = + 1.51   V value is greater than E red o Zn 2 + | Zn = − 0.762   V and E red o Ag + | Ag = + 0.80   V . Thus, only Zn and Ag will be oxidised.