Question

A button cell used in watches functions as following
Zn(s)+Ag2O(s)+H2O(l)⇌2Ag(s)+Zn2+(aq)+2OH−(aq)
If half cell potentials are
Zn2+(aq)+2e−→Zn(s);Eo=−0.76V
Ag2O(s)+H2O(l)+2e−→2Ag(s)+2OH−(aq),Eo=0.34V
The cell potential will be -

Answer 1

Answer:

213.04 kJ

Explanation:

Using the formula for potential standard cell -

e°cell = E° right  – E°left  

e°cell = 0.344 – ( – 0.76)  

e°cell = 0.344+0.076 V  

e°cell = +1.104 V

Since, in a balanced reaction there are always two electrons that are being transferred, thus n = 2

We know that, Faraday constant, F = 96500 C mol−1  and e°cell = + 1.104 V

Using the formula -  

∆rGθ = – nFe°cell

= −2 × 96500 × 1.104

= −212304

= −212304J mol−1

= −212.304kJ mol−1

= −213.04 kJ

Therefore, the potential of cell is 213.04 kJ.

Answer 2

Answer:

1.10V

Explanation: