In the balanced equation for the combustion of 1 mole of benzoic acid, C6H 5COOH(s) at temp. T, the difference between enthalpy change and internal energy change is equal to

Options

A. `-(RT)/(2)`
B. `(-3)/(2)RT`
C. `(5)/(2)RT`
D. `(RT)/(2)`

Answer

A

Explanation

`C_6H_5OOH_s + 15/2 O_(2(g)) rarr 7 CO_(2(g)) +3H_2O_((l))`
`Delta n_((g))=7-15/2=(-1)/(2)`
`Delta H-Delta U = (-RT)/(2)`