The heat of formation of `CO and CO_(2)` are `-26.4kCal and -94 kCal ` , respectively. Heat of combustion of carbon monoxide will be

Options

A. `+26.4` kcal
B. `-67.6` kcal
C. `-120.6` kcal
D. `+52.8` kcal

Answer

B

Explanation

`CO_((g))+1//2O_(2(g)) to CO_(2(g))`
`DeltaH_C^0 (CO)=[DeltaH_f (CO_2)-DeltaH_f(CO)+DeltaH_f (O_2)]`
`DeltaH_C^0(CO)`=-94 K Cal -[-26.4 K Cal +0]
`DeltaH_C^0(CO)`=-94 K Cal+26.4 K Cal
`DeltaH_C^0` (CO)=-67.4 K Cal