[mike_302]

So we are taught the one method: put the enthalpy change quantity in the equation as if it were another piece (either a product or a reactant) . From what we are basically told, the main component will be the component that has a ratio of 1 where as everything else might have fractions or something... They could also be 1 as well, but the main reactant or product will always be... 1.

My attempt at understanding this goes like this:

the quantitative enthalpy change in the reaction has a unit of kJ . Not kJ/mol ... But in reality, it's kJ/(main component, which is always to ratio of 1 mol anyways)

Is this right? What can be corrected?

[enahs]

Huh?

[mike_302]

Lol. ok

example

C6H14 + 19/2 O2 --> 6 CO2 + 7 H2O    delta H (SATP) = -4163 kJ    (this is right off a worksheet we are given)

We are told that the enthalpy here (delta H, degree sign --> enthalpy at SATP) equals -4163 kJ ... not kJ per mol.

But C6H14 is one mole .
Couldn't it be said that the enthalpy change here is   -4163 kJ/mol of hexane ?       

Seeing it like this helps me see the whole thing as 1 big set of ratios

[enahs]

Yes, for that reaction it is -4136 kJ/mol hexane.

Enthalpies are virtually always reported as per mol.

You could also divide it by 19/2 and put in in per mol of O2 in that reaction....but that is just silly.

[mike_302]

Hey! thanks. Awesome reply. Totally answers what I was looking for. Really 

Seeing it this way: I understand that all we are really doing with representing molar enthalpy in the reaction is adding it as another piece of the puzzle, with ratio of 1

Much appreciated!