My question is how would you tell if the product of an reaction has more or less entropy than the reactants?

For example, in glycolysis, when glyceraldehyde-3-phosphate becomes 1-3 bisphosphoglycerate, BPG has less free energy and more entropy than G3P. Anyone able to give me a rundown as to how you would know? Thanks in advance.

  • $\begingroup$ The way you have formulated your question contains a major error. You can talk about the change in free energy or entropy in an overall chemical reaction, and entropy is not an intrinsic feature of a molecule but of the system as a whole. That said, an answer to your question on meauring entropy can be found on SE Chemistry, here.. $\endgroup$ – David Nov 6 '17 at 14:44
  • $\begingroup$ @David I understand that, however the question was phrased like that on a test, as in which molecule (product) has a higher entropy than their reactants, in a chemical reaction. I know the entropy in terms of a system, but was just wondering if anything applies to a specific molecule. Thanks though. $\endgroup$ – ImaginingBears Nov 6 '17 at 14:48
  • $\begingroup$ I must say that in biochemistry the emphasis is on the free energy change of reactions. I am not sure, but imagine that there is generally considered to be no change in entropy of the molecules, unless one is considering the environment (hydrophobic or hydrophilic) or whether a polymeric chain is ordered or not (as here). $\endgroup$ – David Nov 6 '17 at 17:09

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