Question

Which of the following reactions would have the most negative ∆s° value?

A) N₂(g) + 3 Cl₂(g) → 2 NCl(g)
B) CaSO₄ ·7H₂O(s) → CaSO₄(s) + 7 H₂O(g)
C) 2 K(s) + O₂(g) → 2 KO(s)
D) NH₃(g) + HBr(g) → NH₄Br(s)
E) 2 H₂(g) + O₂(g) → 2 H₂O(g)

Answer 1

Among the given reactions, the reaction that would have the most negative ∆s° value is option E, 2 H₂(g) + O₂(g) → 2 H₂O(g). This is because the reaction leads to a decrease in the number of molecules, resulting in a decrease in entropy.

Step-by-step explanation:

Among the given reactions, the reaction that would have the most negative ∆s° value is option E, 2 H₂(g) + O₂(g) → 2 H₂O(g).

Entropy (∆s°) is a measure of the randomness or disorder in a system. In this reaction, two molecules of hydrogen gas (H₂) and one molecule of oxygen gas (O₂) combine to form two molecules of water vapor (H₂O). The number of molecules decreases from three to two, resulting in a decrease in entropy. Since this reaction leads to a decrease in entropy, it would have the most negative ∆s° value.