Relative entropy levels

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Lucia H 2L
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Relative entropy levels

Postby Lucia H 2L » Sun Feb 11, 2018 12:45 am

When looking at reactions and deciding whether entropy will increase or decrease from reactants to products, what are all of the contributing factors? I know that more moles, more gas relative to other states, dissolution, and complex molecules with a lot of positions will generally have more entropy. But would a complex molecule have more entropy than a free ion, such as H+ in an aqueous solution? These seem to conflict.

sahiltelang-Discussion 1J
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Re: Relative entropy levels

Postby sahiltelang-Discussion 1J » Sun Feb 11, 2018 9:23 am

One of the things that we look for if we see a decrease or increase in high entropy substances. For example, if there is a decrease in number of moles of gas from reactants to products that is an example of entropy decrease. Also if we go from many smaller simple compounds to a fewer number of complex molecules, we have an entropy decrease.

Yixin Angela Wang 2H
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Joined: Thu Jul 27, 2017 3:00 am

Re: Relative entropy levels

Postby Yixin Angela Wang 2H » Thu Feb 15, 2018 3:01 am

Also, as per the third law of thermodynamics, a perfectly organized crystal will have 0 entropy. Otherwise, I would look at the state of the substance in question, because there is a big difference between liquid and gas, but not between solid and liquid. I am not sure, however, if a complex molecule in liquid form would have more or less entropy than a simpler gaseous substance. Which quality would take priority in determining relative entropy?

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