Standard Reaction Enthalpy Calculation

[Charly Ng 1K]

If we were to use the standard enthalpy of formation to calculate standard reaction enthalpies, would we be told what the most stable form of the reactants are? or are there specific ones we need to memorize?

[905783577]

I think that foundationally all you need to know is that diatomic gases at 1 atm are most stable, but for example knowing graphite was the most stable form of carbon is probably not going to be expected of us.