Consider the reaction H2(g) + Cl2(g) → 2HCl(g)ΔH = −184.6 kJ / mol

If 9.00 moles of H2 react with 9.00 moles of Cl2 to form HCl, what is ΔU (in kJ) for this reaction at 1.0 atm and 25°C? Assume the reaction goes to completion

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".