Using the `DeltaG^(@)` for the reactions
`{:(C+O_(2)rarrCO_(2),DeltaG^(@)=-395kJ//"mole"),(2Al(l)+3//2O_(2)rarrAl_(2)O_(3)(s),DeltaG^(@)=-1269kJ //"mole"),(Al_(2)O_(3)(s)rarrAl_(2)O_(3)("melt"),DeltaG^(@)=16kJ //"mole"):}`
What is the EMF for the cell reaction
`2Al_(2)O_(3)("melt")+3Crarr4Al(l)+3CO_(2)(g)`
The number of electrons involved in the reaction is 12.

Options

A. `-1.14 `volt
B. `-2.28` volt
C. `+1.14` volt
D. `+2.28`volt

Answer

1

Explanation

`{:(2Al_(2)O_(3)("melt") rarr2Al_(2)O_(3)(s),DeltaG_(1)^(@)=-2xx16),(2Al_(2)O_(3)(s)rarr4Al(l)+3O_(2)(g),DeltaG_(2)^(@)=2xx1269),(3C+3O_(2)rarr3CO_(2),DeltaG_(3)^(@)=-3xx395):}`
`2Al_(2)O_(3)("melt")+3Crarr4Al(l)+3CO_(2)(g)`
`DeltaG^(@)=DeltaG_(1)^(@)+DeltaG_(2)^(@_)+DeltaG_(3)^(@)=-32+2xx1269-3xx395=1321KJ`
`DeltaG^(@)=-nFE^(@)implies" "1321xx10^(3)=-12xxE^(@)xx96500`
`E^(@)-1.14Cm^(-1)`