chemistry help! urgent!!?

Question

predict the sign of Delta Ssys for each of the following processes. For each statement select P-Positive, or N-Negative.
A) 2NO2(g) -> N2O4(g)
B) H2S(g) + 1/2O2(g) -> 1/8S8(s) + H2O(g)
C) 2K(s) + F2(g) -> 2KF(s)
D) CaCO3(s) + 2HCl(aq) -> CaCl2(aq) + H2O(l) + CO2(g)
E) 2KClO3(s) -> 2KCl(s) + 3O2(g)

Answer 1

A) 2NO2(g) -> N2O4(g)
a decrease in no of molecules so N

B)H2S(g) + 1/2O2(g) -> 1/8S8(s) + H2O(g)
decrase in the no of gaseous molecules( entropy of solid, in natural state is regarded as 0). so N

C) 2K(s) + F2(g) -> 2KF(s)

due to the same reason as mentioned above the answer is N.

D) CaCO3(s) + 2HCl(aq) -> CaCl2(aq) + H2O(l) + CO2(g)

increase in the no of gaseous molecules, also matter tranfers from solid state to liq state, so the answer is P

E) 2KClO3(s) -> 2KCl(s) + 3O2(g)

increase in the no of gaseous molecules, so P.

Answer 2

Add up the total moles of gas on the left hand side of each, and compare it with the total moles of gas on the right.
If there is an increase, the entropy change is positive.