Which of the following will form a cell with highest voltage?

 

(E0Co2+/Co=−0.28V;E0Ag+/Ag=0.80V)

A. 

 

1M Ag+ , 1M Co2+

B. 

 

2M Ag+ , 2M Co2+

C. 

 

0.1M Ag+ , 2M Co2+

D. 

 

2MA Ag+ , 0.1M Co2+

Asked by s.ojaswini17 | 16th Feb, 2019, 01:02: PM

Expert Answer:

Option D is correct.  
 
 
The cell reaction is 
 
 
2 Ag to the power of plus space space plus space Co space space rightwards arrow space Co to the power of 2 plus end exponent space space plus space space 2 Ag

We space know space that comma

straight E space equals space straight E subscript 0 space plus fraction numerator 0.059 over denominator 2 end fraction log fraction numerator open square brackets Ag to the power of plus close square brackets squared over denominator open square brackets Co to the power of 2 plus end exponent close square brackets end fraction
 
From the equation,
 
Smaller the concentration of [Co2+] and larger the concentration of [Ag+] will produce maximum e.m.f.
 
So the correct option is D, 2 M Ag+ and 0.1 M Co2+.

Answered by Varsha | 18th Feb, 2019, 11:41: AM

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