(a) What are fuel cells ? Give an example of a fuel cell.
(b) Calculate the equilibrium constant `(logK_(c))and Delta_(r)G^(@)` for the following reaction at 298 K.
`Cu_((s))+2Ag^(+)""_((aq))hArrCu^(2+)""_((aq))+2Ag(s)`
Given `E_(cell)^(@)=0.46V and IF=96500 C mol^(-1).`

Explanation

`Cu_((s))+2Ag^(+)""_((aq))hArrCu^(2+)""_((aq))+2Ag""_((s))`
`E_(cell)^(@)=0.46V, " "1F=96500C mol^(-1)`
`DeltaG^(@)=-2nFE_(cell)^(@)impliesn=2`
`DeltaG^(@)=-2xx96500xx0.46 implies" "DeltaG^(@)=-88780J//mol`
`-DeltaG^(@)=2.303RTlogkimplies" "88780=2.303xx8.314xx298logk_(c)`
`logk_(c)=(88780)/(2.303xx8.314xx298)implies" "logk_(c)=15.56`