The difference between the heats of reaction at constant pressure and a constant volume for the reaction `2C_(6)H_(6)(l) + 15O_(2)(g) rarr 12CO_(2)(g) + 6H_(2)O(l)` at `25^(@)C` in `kJ` is

Options

A. `-7.43`
B. `+3.72`
C. `-3.73`
D. `+7.43`

Answer

A

Explanation

`(Delta H)_(p)=(Delta H)_(v) + Delta nRT`
i.e. `Delta H = Delta U + Delta nRT`
`Delta n=(12+0)-(0+15)=-3`
`therefore Delta nRT =-3xx8.314xx10^(-3) xx298`
`=-7.43 kJ`
`therefore Delta H - Delta U =-7.43 kJ`