In the complete combustion of butanol `C_(4)H_(9)OH(l)` if DeltaH is enthalpy of combustion at constant pressure and DetlaE is the heat of combustion at constant volume ,then

Options

A. `DeltaH gt DeltaE`
B. `DeltaH=DeltaE`
C. `DeltaH lt DeltaE`
D. `DeltaH, Delta E` relation cannot be predicted

Answer

A

Explanation

The following equation describe the complete combustion of butanol `C_(4)H_(9)OH`,
`CH_(4)H_(9)Oh(l)+60_(2)(g)to4CO_(2)(g)+5H_(2)O(l)+Heat`
`Delta`n=Moles of gaseous product-
Moles of gaseous reactant
`Delta`n=4-6=-2
In the above reaction ,`Delta`is negative
`thereforeDeltaHltAE`.