From the following data
`CH_(3)OH(l)+(3)/(2)O_(2)(g) rarr CO_(2)(g) +2H_(2)O(l)`
`Delta_(r) H^(@)=-726 kJ mol^(-1)`
`H_(2)(g)+(1)/(2)O_(2)(g) rarr H_(2)O(l), Delta _(r) H^(@)=-286 kJ mol^(-1)`
`C("graphite") +O_(2)(g) rarr CO_(2)(g), Delta _(r) H^(@)=-393 kJ mol^(-1)`
The standard enthalpy of formation of `CH_(3)OH(l)" in "kJ mol^(-1)` is

Explanation

The given data
`CH_(3)OH(l)+(3)/(2)O_(2)(g)toCO_(2)(g)+2H_(2)O(l),Delta_(r)H^(theta)=-726 kJ mol^(-1)`
`C_(("graphite"))+O_(2)(g)toCO_(2)(g),Delta_(c)H^(theta)=-393 kJ mol^(-1)`
`H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l),Delta_(f)H^(theta)=-286 kJ mol^(-1)`
Multiply the3 equation with 2 and then add the three reactions after reversing the equation,
`CO_(2)(g)+2H_(2)O(l)toCH_(3)OH(l)+(3)/(2)O_(2)(g),Delta_(r)H^(theta)=+726 kJ mol^(-1)`
`C_(("graphite"))+O_(2)(g)toCO_(2)(g),Delta_(c )H^(theta)=-393 kJ mol^(-1)`
`2H_(2)(g)+O_(2)to2H_(2)O,H_(2)O(l),Delta_(f)H^(theta)=-572 kJ mol^(-1)`
`C+2H_(2)+(1)/(2)O_(2)toCH_(3)OH,Delta_(f)H^(theta)=-239 kJ mol^(-1)`