HW 8.57

[Wesley_Rugen_1E]

The question asks to determine the reaction enthalpy for the hydrogenation of ethyne to ethane, C2H2(g) + 2H2(g) -> C2H6(g). What happens when we hydrogenate something? What do we add to the equation?

[Grace_Bower_2B]

You're overcomplicating it. Hydrogenation just means adding hydrogen, this case adding hydrogen to ethyne to turn it into ethane. It's not telling you that you have to do something to the equation, just naming the reaction occurring (like combustion)

[Justin_Yi_1J]

To hydrogenate it means to add hydrogen to the molecule. You see in the given reaction H2 is added to the C2H2, making it C2H2. The pi bond breaks between the carbons and the electrons pair with the hydrogen diatomic molecules that also have their bonds broken.