#10 in the sapling

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Shreya Patel- 2D
Posts: 96
Joined: Wed Sep 30, 2020 10:01 pm

#10 in the sapling

Postby Shreya Patel- 2D » Thu Oct 08, 2020 7:45 pm

How do we read chemical structures like in problem number #10 to find the molar mass?

Kyle Walsh 2J
Posts: 75
Joined: Wed Sep 30, 2020 9:48 pm

Re: #10 in the sapling

Postby Kyle Walsh 2J » Thu Oct 08, 2020 7:53 pm

Hi! I totally forgot how to read this stuff too at first lol. Essentially each line has a carbon attached on either end, which is then satisfied by hydrogens. The amount of hydrogens attached is 4 minus however many bonds are connected to the given vertex. So for example, the first diagram with the double-bonded oxygen molecule would have one carbon and three hydrogens at the far left, then one carbon and two hydrogens at the first vertex, one carbon at the next vertex (the one with oxygen), and one carbon and three hydrogens attached at the far right. This means that the overall formula for 2-butanone is C4H8O. It's a bit tricky to explain in-text, looking up a video is what helped me most. Hope this helps! :)

Gian Boco 2G
Posts: 86
Joined: Wed Sep 30, 2020 9:36 pm

Re: #10 in the sapling

Postby Gian Boco 2G » Thu Oct 08, 2020 8:32 pm

I just googled the molar masses of the molecules ahaha. I feel like in the future we would be given the molar masses of molecules that we aren't familiar with such as this.

reva_bajjuri
Posts: 111
Joined: Fri Oct 02, 2020 12:17 am

Re: #10 in the sapling

Postby reva_bajjuri » Thu Oct 08, 2020 9:11 pm

for this problem, is the molar ratio 1:1? if so, how did you determine that for sure without being able to actually write out the chemical formula and balance it?

JoshMoore2B
Posts: 90
Joined: Wed Sep 30, 2020 9:51 pm

Re: #10 in the sapling

Postby JoshMoore2B » Thu Oct 08, 2020 9:41 pm

reva_bajjuri wrote:for this problem, is the molar ratio 1:1? if so, how did you determine that for sure without being able to actually write out the chemical formula and balance it?

For this question in particular, I believe that the diagram shows an organic chemical reaction, and in organic chemistry you will likely run into chemical equations using a diagram of the molecule as opposed to the molecular formula. This diagram is treated as if it is a molecular formula, so it can have stoichiometric coefficients. The absence of stoichiometric coefficients next to the compounds in question 10 implies that each compound is present in molar amounts of 1 (via the invisible 1), and so that context should allow you to determine for sure that the molar ratio is 1:1.

Sophia Kalanski 1A
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Re: #10 in the sapling

Postby Sophia Kalanski 1A » Thu Oct 08, 2020 11:29 pm

Hi! I was lost on reading these too but I figured it out! Every corner is a carbon atom, and every line links it to another atom. The ones that end as like the last line still has a carbon atom at the end along with 3 hydrogen atoms to make each elemental atom complete its orbital (8 electrons). The covalent bond already takes up a part of the electron so for the inner corners, there are 2 hydrogens as opposed to 3. By doing that for 2-butanone, You get (H3)C, (H2)C, C with an O as a double covalent bond, and (H3)C. You add them together and get your molecular formula!

Amanda Bueno-Kling
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Re: #10 in the sapling

Postby Amanda Bueno-Kling » Sat Oct 10, 2020 7:02 pm

Are there any resources that are good for reviewing these structures and how to figure out which atoms they contain? I really struggled with this problem as I did not know how to figure out what the diagrams meant.


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