The heat of combustion of carbon is -94 kcal at 1 atm pressure. The intrinsic energy of `CO_(2)` is

Options

A. `+94` kcal
B. `-94` kcal
C. `+47` kcal
D. `-47` kcal

Answer

B

Explanation

`C(s) + O_(2)(g) rarr CO_(2)(g), Delta H= -94`K kcal
`Delta n_(g)= 1-1= 0`
`Delta H= Delta E + Delta n_(g) RT rARr Delta E= -94` kcal
`Delta E= E_(CO_(2)) - E_(C)- E_(O_(2))`
`-94 = E_(CO_(2)) - 0-0` [Internal energy of elements= 0]
`E_(CO_(2)) = -94` kcal