SDN Members don't see this ad. (About Ads) So we all know deltaH = Hprod - Hreacts. TPR GChem passage 36, Q5: Based on the following data: S(r)+O2->SO2 dH= - 297.0 S(m)+O2->SO2 dH= - 297.1 What is the enthalpy change in the transformation of S(r) to S(m)? So I saw that we'd need to flip the second equation for this to work, right? My new equation was: S(r)+O2->SO2->S(m)+O2 Therefore, products - reactants gave me dH = 298.1 - (-297) = 594.1 Intuition kicked in and I chose +0.1 instead of it and I was right.... but why isnt it 594.1?