Question

say

A -> B + 5kJ

would reactants have more enthalpy or products have more enthalpy?

I think first, the delta H would be negative. So H final must be less than H initial. So reactants have more enthalpy?

Answer 1

I think you are right although the question (and your answer) implies that we know the <i>absolute</i> enthalpy and we never know that. We can measure the change in enthalpy but we can't measure the absolute value of the enthalpy. That's why we have an arbitrary standard.