Aqueous and gaseous elements and compounds?

[lha08]

Homework Statement

Predict the sign of ΔS(sys) for each of the following processes:
a) Zn(s)+2HCl(aq)-->H2(g)+ZnCl2(aq)
b) CH3CH2CH3(g)+5O2(g)-->3CO2(g)+4H2O(l)

Also, I'm not sure but when we're evaluating questions like these, do we count the number of moles only of solids, aqueous and gaseous elements and compounds?

Homework Equations

The Attempt at a Solution

The first one, ΔS is POSITIVE but I'm not sure why though because 3 moles reactants-->2 moles reactant (should be more ordered (negative)...) thanks.

 

[nobahar]

Zn(s)+2HCl(aq)-->H2(g)+ZnCl2(aq)

The states are changing from more ordered ones (solid) to less ordered ones (gas) overall. This is an increase in entropy.
Hope that helps, I'm pretty confident its right.

 

[Mapes]

Out of solids, liquids, and gases, one state typically has a very large molar entropy that dominates over the others.