The enthalpies of combustion of carbon and carbon monoxide are `-393.5` and `-283` kJ `mol^(-1)` respectively. The enthaly of formation of carbon monoxide per mole is :

Options

A. `-676.5 kJ`
B. 676.5 kJ
C. 110.5 kJ
D. `-110.5 kJ`

Answer

D

Explanation

`C(s)+O_(2)(g)rarrCO_(2)(g)`
`DeltaH=-393.5 kJ mol^(-1)`
`CO(g)+1//2O_(2)(g)rarrCO_(2)(g)" ….(i)"`
`DeltaH=-283 kJ mol^(-1)" ….(ii)"`
On substracting equation (ii) from equation (i)
we get
`C(s)+O_(2)(g)rarrCO(g), DeltaH=-110.5 kJ mol^(-1)`
The enthaply of formation of carbon monoxide per mole
`=-110.5 kJ mol^(-1)`.