NEET2006ChemistryElectrochemistryActual
Assertion : For the Daniel cell, Zn | Zn ²⁺ | Cu ²⁺ | Cu with E_ cell =1.1 ~V , the application of opposite potential greater than 1.1 ~V results into flow of electron from cathode to anode. Reason : Zn is deposited at anode and Cu is dissolved at cathode.
Options
- AIf both assertion and reason are true and reason is the correct explanation of the assertion
- BIf both assertion and reason are true but reason is not the correct explanation of the assertion
- CIf assertion is true, but reason is false
- DBoth assertion and reason are false statements.
Correct answer
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
Step-by-step solution
If the opposing potential becomes slightly larger than that of the cell, the direction of current flow is reversed, and so is the cell reaction. Now zine ions are converted to zine at one electrode and Cu is converted into copper ion and the overall cell reaction becomes Zn ²⁺+ Cu Zn + Cu ²⁺