Question on Test 2

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505106414
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Question on Test 2

Postby 505106414 » Tue Nov 26, 2019 4:06 pm

Can someone explain the sigma and pi bond question from Test 2? I believe there was also a hydrogen bonding component to the question as well.

NRobbins_1K
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Re: Question on Test 2

Postby NRobbins_1K » Tue Nov 26, 2019 4:13 pm

The question asked us to identify every bond in the molecule. Every single bond contains one sigma bond, every double bond contains one of each of pi and sigma bonds, and triple bonds (which I don't believe were on that question) contain two pi bonds and one sigma bond. As for the hydrogen bonding component, there was a bonding site for each of the lone pairs on the electronegative atoms nitrogen and oxygen, as well as one on the hydrogen which was bonded to an electronegative atom.

Kishan Shah 2G
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Re: Question on Test 2

Postby Kishan Shah 2G » Tue Nov 26, 2019 4:56 pm

For this question, you had to be able to identify that all the single bonds had a sigma bond in it and that all the double bonds that a sigma bond and a pi bond in it. When counting the number of hydrogen bonding sites you need to include the H-bonds already present and the lone pairs on N,O, or F.

Emily_4B
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Re: Question on Test 2

Postby Emily_4B » Wed Nov 27, 2019 12:26 am

Kishan Shah 1G wrote:For this question, you had to be able to identify that all the single bonds had a sigma bond in it and that all the double bonds that a sigma bond and a pi bond in it. When counting the number of hydrogen bonding sites you need to include the H-bonds already present and the lone pairs on N,O, or F.

So how many hydrogen bonding spots should we have gotten?

Justin Quan 4I
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Re: Question on Test 2

Postby Justin Quan 4I » Wed Nov 27, 2019 11:36 am

Emily_4B wrote:
Kishan Shah 1G wrote:For this question, you had to be able to identify that all the single bonds had a sigma bond in it and that all the double bonds that a sigma bond and a pi bond in it. When counting the number of hydrogen bonding sites you need to include the H-bonds already present and the lone pairs on N,O, or F.

So how many hydrogen bonding spots should we have gotten?

The correct response is 11 hydrogen bonding spots. 8 of those spots comes from the negativity charged O and N atoms caused by their lone pairs. The other three sites are the slightly positively charged hydrogen atoms.

Camellia Liu 1J
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Re: Question on Test 2

Postby Camellia Liu 1J » Wed Nov 27, 2019 11:43 am

There is actually also one hydrogen bond between H-N. Maybe we were graded differently or something but my answer was 9 hydrogen bonding sites, with 8 lone-pair sites and one hydrogen bond.

Justin Sarquiz 2F
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Re: Question on Test 2

Postby Justin Sarquiz 2F » Wed Nov 27, 2019 11:45 am

There were different versions of the test, but essentially each lone pair on a N, O, or F counts as one hydrogen bonding site. Each hydrogen attached to a N, O, or F also counts as a hydrogen bonding site.

Matthew ILG 1L
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Re: Question on Test 2

Postby Matthew ILG 1L » Wed Nov 27, 2019 4:42 pm

Kishan Shah 1G wrote:For this question, you had to be able to identify that all the single bonds had a sigma bond in it and that all the double bonds that a sigma bond and a pi bond in it. When counting the number of hydrogen bonding sites you need to include the H-bonds already present and the lone pairs on N,O, or F.

Why are the H-bonds included when counting? Can't hydrogen atoms only form one bond, so how would they still be included as a possible h-bond location?

Jorge Ramirez_4H
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Re: Question on Test 2

Postby Jorge Ramirez_4H » Wed Nov 27, 2019 8:15 pm

How much points would we lose if we just didn't get the hydrogen bonding sites?

Emily_4B
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Re: Question on Test 2

Postby Emily_4B » Sat Nov 30, 2019 3:45 pm

Jorge Ramirez_4H wrote:How much points would we lose if we just didn't get the hydrogen bonding sites?

4 points

CMaduno_1L
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Re: Question on Test 2

Postby CMaduno_1L » Sat Nov 30, 2019 5:57 pm

In response to Matthew ILG 1L, I believe the term "hydrogen-bonding sites" refers to the places where hydrogen bonds can potentially form as well as where they already exist, which is why you would include the H-bonds already present in order to find the total number of bonding sites.

VPatankar_2L
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Re: Question on Test 2

Postby VPatankar_2L » Sat Dec 07, 2019 10:01 pm

If the question asks "how many atoms on the structure would form a hydrogen bond?" you would just count the number of atoms that would have hydrogen bonding sites. But if it asks for the number of hydrogen bonding sites, you would count each available lone pair where bonding could occur.


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