Another Kinetics/Entropy question, posted below shortly.

Question

mendicant_bias · Answer

"The brown color associated with photochemical smog is due to NO2(g), which is involved in an equilibrium with N2O4(g) in the atmosphere.

2 NO2(g)  N2O4(g)

For this reaction ΔH° is negative and ΔS° is positive. What are the signs of ΔS°surr and ΔS°univ? "

mendicant_bias · Answer

What I'm confused about is how I deal with the delta S-universe, delta S-surroundings term.

I don't know how this problem is different from the original.

mendicant_bias · Answer

@aaronq

aaronq · Answer

I dont see how the $\Delta S^o$ for the reaction can be positive if you're decreasing the amount of molecules present, from 2 to 1.

aaronq · Answer

$\Delta S_{uni}=\Delta S_{surr}+\Delta S_{system}$

mendicant_bias · Answer

Let me screencap the response so I'm sure we're looking at the same thing: