Discussion Forum



1)

For hydrogen -oxygen fuel cell, the cell reaction is 

$2H_{2}(0)+O_{2}(g)\rightarrow 2H_{2}O(l)$

 if   $\triangle G_f^0  (H_{2}O)=-237.2kJmol^{-1}$   , then emf of this cell is 


A) +2.46 V

B) -2.46 V

C) +1.23 V

D) -1.23 V

Answer:

Option C

Explanation:

 We know   $\triangle$ G0= -nFE0

$\therefore$        $E^{0}=\frac{\triangle G^{0}}{nF}$

 $= +\frac{237.2\times1000J}{2\times96500}=1.23 V[\therefore n=2]$