Question

in most exergonic reactions, before products can be formed, the reactants must first overcome a thermodynamic barrier known as the...

entropy of the reaction.

energy conservation of the reaction.

chemical equilibrium of the reaction.

activation energy of the reaction.

Explanation:

Exergonic reactions release energy. But for reactants to form products, they need to overcome a barrier. Activation energy is the minimum energy required for a reaction to occur. Entropy is a measure of disorder. Energy conservation is a principle (energy is neither created nor destroyed). Chemical equilibrium is a state where forward and backward reaction rates are equal. Only activation energy is the thermodynamic barrier reactants must overcome.

Answer:

activation energy of the reaction.