Answer:
Enthalpy is delta-H-
We need to look at the molecule and determine which bonds are broken adn which bonds are formed.
Bonds that are broken are H-H (from the H2 molecule) and the C=O from acetone.
their energies add up like this: 436 kJ + 745 kJ = 1181 kJ
looking at the bonds formed, these are C-O, O-H, and C-H. these add up to 1229 kJ
solving for delta H by taking the sum of the broken bonds and subtracting the sum of the formed bonds, like so:
1181 - 1229 = -48 kJ
