Question

Entropy (∆S) is a measure of disorder. In the Diels-Alder reaction you performed, do you expect the ∆S to be positive or negative?

Options:
a) Positive
b) Negative
c) Neutral
d) Undefined

Answer 1

In a Diels-Alder reaction, the entropy change is expected to be negative since the reaction results in fewer microstates due to the formation of a cyclic compound from two separate molecules.

Step-by-step explanation:

Entropy, often denoted as ∆S, measures the disorder or randomness within a thermodynamic system. In the context of the Diels-Alder reaction, which is a cycloaddition process where diene and dienophile react to form a cyclic compound, we expect a decrease in disorder. This is because the reaction involves the combination of two separate molecules into one, hence reducing the number of possible microstates. As such, the entropy change (∆S) for the Diels-Alder reaction would be expected to be negative. This is because fewer microstates are available in the product compared to the combined microstates of the reactants.