The standard heats of formation of `CH_(4)(g), CO_(2)(g)` and `H_(2)O(g)` are `-76.0, -390.0`, and `-240.0 kJ mol^(-1)`, respectively. Calculate the amount of heat evolved by burning `1m^(3)` of methane measured under normal conditions.

Explanation

The required for the conustion of mathane is:
`CH_(4) +2O_(2)rarr CO_(2)+2H_(2)O,DeltaH=?`
`DeltaH^(Theta) = Delta_(f)H^(Theta)("product")-Delta_(f)H^(Theta)("reactants")`
`=Delta_(f)H_((CO_(2)))^(Theta)+2xxDelta_(f)H^(Theta)H_((H_(2)O))^(Theta)-Delta_(f)H_((CH_(4)))^(Theta)-2Delta_(f)H_((O_(2)))^(Theta)`
`=- 390.0 - 2 xx 240.0 -(-76.0) - 2xx0`
`=- 718.0 kJ mol^(-1)`.
Heat evolved by buring `22.4L` (1mol) methane `= 718.0 kJ`.
So, heat evolved by buring `1000L (1m^(3))` methane
`=-(718.0)/(22.4) xx 1000 =- 32053.5 kJ`