Which relationship or statement best describes ΔS° for the following reaction?

Question

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

(A) ΔS° ≈ 0 (B) ΔS° < 0 (C) ΔS° > 0 (D) ΔS° =ΔH° /T

(E) More information is needed to make a reasonable prediction.

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Answer is (B)

and if the reaction change to

BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq).

Why the answer is also (B)?

Answer 1

最佳解答

The answer in both cases in B because you are increaseing in disorder (ΔS). The reason I know this is that n the left side of the top equation there is 4 molecules and on the right there are 5 molecules, ie more disorder.

For the bottom equation there are 2 molecules on the left, going to three molecules on the right.

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