Well, if you were to determine the delta H, okay?

It would simply be the products minus the reactants.

That would be the final minus the initial.

So in our picture on the left, the final is here, that's your products.

Your initial is here, that's your reactant.

So this is how much, even though we don't know how much that is,

we can know that one's bigger than the other.

So here is the H final, here is the n, H initial up top.

And if we wanted to change, we do products minus n, reactants.

Well the products have a low value, so

this would be small in this picture on the left.

The reactants have a large value in comparison.

So, what would be the sign of that?

A small number minus a large number.

When you are dealing with an exothermic reaction,

the delta H will always be negative.

Now this is like what we saw with q.

Q was negative for an exothermic reaction, so

there's the connection we're seeing there.