NEET2022ChemistryElectrochemistryActual
At 298   K , the standard electrode potentials of Cu 2 + / Cu ,   Zn 2 + / Zn ,   Fe 2 + / Fe and Ag + / Ag are 0 . 34   V , - 0 . 76   V , - 0 . 44   V and 0 . 80   V , respectively. On the basis of standard electrode potential, predict which of the following reaction cannot occur?
Options
- ACuSO 4 ( aq ) + Fe ( s ) → FeSO 4 ( aq ) + Cu ( s )
- BFeSO 4 ( aq ) + Zn ( s ) → ZnSO 4 ( aq ) + Fe ( s )
- C2 CuSO 4 ( aq ) + 2 Ag ( s ) → 2 Cu ( s ) + Ag 2 SO 4 ( aq )
- DCuSO 4 ( aq ) + Zn ( s ) → ZnSO 4 ( aq ) + Cu ( s )
Correct answer
C. 2 CuSO 4 ( aq ) + 2 Ag ( s ) → 2 Cu ( s ) + Ag 2 SO 4 ( aq )
Step-by-step solution
The given standard reduction potentials of Zn ,   Cu ,   Ag and Fe are; E ° Zn 2 + Zn = - 0 . 76   V ,   E ° Cu 2 + cu = 0 . 34   V E ° Ag + Ag = 0 . 80   V ,   and   E ° Fe 2 + Fe = - 0 . 44   V   The condition for reaction to occur, E ° Cell = E ° SRP reduction   reaction - E ° SRP oxidation   reaction must have the positive value. A   Cu 2 + aq + Fe → Cu   + Fe 2 + aq E ° Cell = 0 . 34 + 0 . 44 E &