Standard free energies fo formation (in kJ/ mol) at 298 K are -237.2 - 394.4 and -8.2 for `H_(2)O(l)CO_(2)(g)` and pentane (g) respecitively the value of `E_(cell)^(@)` for the pentane oxygen fuel cell is

Options

A. 1.98 V
B. 2.0968 V
C. 1.0968 V
D. 0.0968 V

Answer

C

Explanation

Given `triangle G_(H_(2)O)^(@)(I)=(-237.2 KJ)//"mol"`
`triangle_(CO_(2))^(@)(g)=-394.4 KJ//"Mol"`
`triangle G_(C_(5)H_(12)(g)^(@) =- 8.2 KJ//"mol"`
`C_(5)H_(12)+8O_(2) rarr 5CO_(2)+6H_(2)O`
`triangle G^(@)=5xxtriangle G_(CO_(2))^(@)+6xx triangle_(H_(2)^(@)-triangle_(C_(5)(H_(12)^(@))+8xx triangle G_(O_(2))^(@)`
In pentane oxygen fuel cell 32 electrons are involved
`triangle G^(@)=- nFE^(@)`
`-3387 xx10^(3)=- 32 xx96500xxE^(@)`
`therefore 16^(O)+32 E^(-) rarr 16 O^(2)`
`E^(@)=(3387xx10^(3))/(32xx96500)=1.0968 V`