9.27 A

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Michelle Dong 1F
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Joined: Fri Sep 29, 2017 7:04 am

9.27 A

Postby Michelle Dong 1F » Tue Jan 30, 2018 10:03 pm

Which substance in each of the following pairs has the higher molar entropy at 298 K?
(a) HBr (g) or HF(g)

Can someone explain why HBr (g) has higher molar entropy? How can you tell if something has higher molar entropy in general? Is there a trend?

Mitch Mologne 1A
Posts: 74
Joined: Fri Sep 29, 2017 7:04 am

Re: 9.27 A

Postby Mitch Mologne 1A » Tue Jan 30, 2018 10:12 pm

The more particles the molecule has, the higher the molar entropy. Because HBr is a bigger molecule (thus more particles) it will have the higher molar entropy.

SitharaMenon2B
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Joined: Thu Jul 27, 2017 3:01 am

Re: 9.27 A

Postby SitharaMenon2B » Tue Jan 30, 2018 10:15 pm

The trend is that the more complex a molecule is, the higher the molar entropy is. This is because a more complex molecule with more atoms can be arranged in a lot more configurations.

Felicia Fong 2G
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Joined: Sat Jul 22, 2017 3:00 am

Re: 9.27 A

Postby Felicia Fong 2G » Sun Feb 04, 2018 12:57 pm

Bromine is farther down the periodic table than Flourine. Thus, Bromine is larger and contains more elementary particles than F in HF. More particles means more entropy. To compare entropies, look at the states of matter if they are different. Entropy increases from solid to liquid to gas.

Sarah Clemens 1B
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Joined: Fri Sep 29, 2017 7:03 am

Re: 9.27 A

Postby Sarah Clemens 1B » Mon Feb 05, 2018 12:48 am

Since Br is a bigger molecule than F it makes it more complex which means it also has a larger entropy.

Jana Sun 1I
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Joined: Sat Jul 22, 2017 3:00 am

Re: 9.27 A

Postby Jana Sun 1I » Thu Feb 08, 2018 12:24 am

Felicia Fong 2G wrote:Bromine is farther down the periodic table than Flourine. Thus, Bromine is larger and contains more elementary particles than F in HF. More particles means more entropy. To compare entropies, look at the states of matter if they are different. Entropy increases from solid to liquid to gas.


What exactly are the "elementary particles" you mention?


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