COMEDK2012ChemistryElectrochemistry
Zn (s)+ Cl ₂(1 ~atm ) Zn ²⁺+2 Cl ⁻ ; E^ =2.0 ~V To increase the emf of the above cell
Options
- A[ Zn ²⁺ ] should be increased
- B[ Zn ²⁺ ] should be decreased
- C[ Cl ⁻ ] should be increased
- Dpartial pressure of Cl ₂ should be decreased
Correct answer
B. [ Zn ²⁺ ] should be decreased
Step-by-step solution
According to Nernst equation for a cell Zn (s)+ Cl ₂(1 ~atm ) Zn ²⁺+2 Cl ⁻ ; E^ =2 ~V E=E^ - 0.059 2 [ Zn ²⁺ ] [ Cl ⁻ ]² A s [ Zn ²⁺ ] decreases E_ emf of cell increases.