From the following data, calculate the enthalpy change for the combustion of cyclopropane at 298 K. The enthalpy of formation of `CO_(2)(g), H_(2)O(l)` and propene (g) are - 393.5, -285.8 and 20.42 kJ ` "mol"^(-1)` respectively.The enthalpy of isomerisation of cyclopropane to propene is `-33.0 kJ "mol"^(-1)`.

Explanation

The given equations are :
(i) `C(s) + O_(2)(g) to CO_(2)(g) DeltaH = -393.5 kJ`
(ii) `H_(2)(g) + 1/2 O_(2)(g) to H_(2)O(l) DeltaH = -285.8 kJ`
(iii) `3C(s) + 3H_(2)(g) to C_(3)H_(6)(g) DeltaH = 20.42 kJ`
(iv)
The required equation(v) can be obtained by multiplying equation(i) and (ii) by 3 and adding these, then subtracting equation(ii) from these and adding equation(iv), i.e
`DeltaH = [Eq.(i) xx 3] + [Eq.(ii) xx 3] - [Eq.(iii)] + [Eq.(iv)]`
`= (-395.5 xx 3)+(-285.8 xx 3) - (20.42) + (-33.0)`
` = -2091.32 kJ`