Answer:
using bond energies = - 37 kJ
using enthalpies of formation = - 45.7 kJ
Explanation:
From the reaction;
CH2═CH2(g) + H2O(g) -------> CH3CH2OH(g)
From the above reaction; there are 4 (C-H) bonds , 1 ( C=C) and 2 (H-O) of ethene which forms 5(C-H) bonds, 1 (C-C) and 1 (C-O) and 1(H-O) bonds.
Using Bond Energies; the heat of the reaction can be written as:
∑ energy of old bond breaking + ∑ energies of the new bond formation.
∑
+ ∑
∑
+ ∑
-37 kJ
To calculate the heats of reaction by using enthalpies of formation; we have:
∑
- ∑
∑
- ∑
(-235.1 kJ) - [(+52.47 kJ) + (-241.826 kJ)]
-45.7 kJ