Everything tends toward its lowest energy conformation. Would it be correct to infer, then, that in a non-spontaneous reaction, some form of spontaneous reaction(s) must occur in order for the non-spontaneous reaction to proceed?

1 Answer
Apr 29, 2018

No. If a reaction would be nonspontaneous, it just won't be thermodynamically feasible, because even if the reactants are lower in energy than the products, it would be that entropy disfavors the reaction. If an alternative and spontaneous process then occurs, generally the original reaction would no longer be relevant.

Furthermore, a catalyst would not be recommended because they improve the kinetics, and do nothing for the thermodynamics.


Here is an example of a nonspontaneous reaction that can never be made thermodynamically favorable or kinetically favorable to happen:

An alkene will never donate electrons into a nucleophile. No catalyst will make that happen; by definition, a nucleophile wants to donate an electron pair, not receive it.

Instead, to react with #"NH"_3#, a separate reaction had to occur to form an alkyl halide for the formation of an amine to be remotely possible, and even then, that's an entirely different reaction because the reactant is not an alkene anymore...