Question

Which of the following processes would be expected to have a positive `Delta"S"` value?

Which of the following processes would be expected to have a positive `Delta"S"` value?

A) `2"NO"_text[(g)] + "O"_2""text[(g)] -> 2"NO"_2""_text[(g)]`
B) `"Cl"_2""_text[(g)] + "Br"_2""_text[(g)] -> 2"ClBr"_text[(g)]`
C) `"N"_2""_text[(g)] + 3"H"_2""_text[(g)] -> 2"NH"_3""_text[(g)]`
D) `"H"_2"O"_text[(l)] -> "H"_2"O"_text[(s)]`
E) `"CaCO"_3""_text[(s)] -> "CaO"_text[(s)] + "CO"_2""_text[(g)]`

Answer 1

Surely, this is `E.`?

Explanation:

An INCREASE in entropy results from an increase in DISORDER....and this is what entropy is: `"the statistical probability for disorder"`.

For `A-C` we gots entropically neutral or NEGATIVE processes in terms of moles of reactants versus moles of products. For `D` we gots the transition liquid to solid; inherently an entropically NEGATIVE process...

But for `E` we gots the evolution of a GAS, from a solid....and this should be ENTROPICALLY POSITIVE...