# 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 $\Delta \text{S}$ value? A) $2 {\text{NO"_text[(g)] + "O"_2""text[(g)] -> 2"NO"_2}}_{\textrm{\left(g\right)}}$ B) ${\text{Cl"_2""_text[(g)] + "Br"_2""_text[(g)] -> 2"ClBr}}_{\textrm{\left(g\right)}}$ C) ${\text{N"_2""_text[(g)] + 3"H"_2""_text[(g)] -> 2"NH"_3}}_{\textrm{\left(g\right)}}$ D) ${\text{H"_2"O"_text[(l)] -> "H"_2"O}}_{\textrm{\left(s\right)}}$ E) ${\text{CaCO"_3""_text[(s)] -> "CaO"_text[(s)] + "CO"_2}}_{\textrm{\left(g\right)}}$

May 18, 2018

Surely, this is $E .$?
An INCREASE in entropy results from an increase in DISORDER....and this is what entropy is: $\text{the statistical probability for disorder}$.
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...