Entropy Changes in Chemical Reactions and How to 17 6 Calculate S RXN Standard State Pure gas at 1atm Pure liquid or solid at 1atm and 25 C Pure substance in solution at 1M S RXN S products S reactants S RXN the standard entropy change for a reaction HOW TO COMPARE RELATIVE ENTROPIES Effect of State of Matter for same substances The solid form would have the lowest S and the gas form would have the highest S The liquid would be in between higher than the solid but lower than the gas Effect of Molar Mass for elements in the same state of matter S increases as molar mass increases for elements in the same state of matter Effect of Molecular Complexity S increases with increasing molecular complexity for molecules in the same state of matter A molecule would have a higher S than an atom Effect of dissolution Aqueous solutions have higher S than solids because they completely dissociate into two ions in solution
View Full Document
Unlocking...