Positive Delta S: H2 + I2 --> 2HI, N2O4 from NO2

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The discussion focuses on determining which chemical reactions exhibit a positive change in entropy (delta S). The reactions analyzed include H2 + I2 --> 2HI and 2NO2 --> N2O4. The consensus is that the reaction H2(g) + I2(s) --> 2HI(g) is likely to have a positive delta S due to the increase in the number of gas molecules, while the reaction 2NO2(g) --> N2O4(g) is expected to have a negative delta S because it involves the formation of a single molecule from two gas molecules.

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Question: Which of the following would probably have a positive delta S value?

He (g, 2atm) --> He (g, 10 atm)
H2(g) + I2(s) --> 2HI (g)
2Ag(s) + Br2(l) --> 2AgBr(s)
O2(g) --> O2(aq)
2NO2(g) --> N2O4(g)

My answer:
Well, I know that when a gas is pressurized, there are less states it can be in, so the first one's out.
I know that when a liquid becomes a solid, there are less possible states it can be in, so the third one's out.
I know that when a gas becomes an aqueous solution, there are less possible states it can be in, so the fourth one's out.

That leaves the second and fifth ones.
Can someone explain this to me?
 
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The fifth one has two molecules reacting to form one molecule.

The second one has two molecules that are diatomic becoming two molecules that are composed of different species.
 

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