Given that `C+O_(2)rarrCO_(2),DeltaH^(@)=-xKJ` and `2CO+O_(2)rarr2CO_(2),DeltaH^(@)=-yKJ` The enthalpy of formation of carbon monoxide will be

Options

A. `(y-2x)/(3)`
B. `(y-2)/(2)`
C. `(2x-y)/(2)`
D. `(x-y)/(y)`

Answer

B

Explanation

`C(s)+O_(2)(g)toCO_(2)(g)," "DeltaH^(@)=-xkJ`
`underline(CO_(2)(g)CO(g)+(1)/(2)O_(2)(g)," "DeltaH^(@)=+(y)/(2)kJ)`
On adding `underline(C(s)+(1)/(2)O_(2)(g)toCO(g)," "DeltaH^(@)=(y-2x)/(2))`