AP EAMCET202021 Sep 2020Morning ShiftChemistryElectrochemistryActual
In the Daniell cell, ( Zn | Zn ²⁺ | Cu ²⁺ | Cu ), when an external voltage is applied such that (E_ external >E_ cell ), current flows from.........
Options
- A( Zn ) to ( Cu )
- BCu to ( Zn )
- Cno current flows
- Ddata insufficient
Correct answer
A. ( Zn ) to ( Cu )
Step-by-step solution
On applying an external voltage greater than (1.1 ~V ) in a Daniell cell, the current flows in the reverse direction i.e., from ( Zn ) to ( Cu ) (cathode to anode) and electrons flow from ( Cu ) to ( Zn ). ( Zn ) is deposited at ( Zn ) electrode and ( Cu ) dissolves at ( Cu ) electrode. The reaction is ( Zn ²⁺+ Cu Zn + Cu ²⁺ )