Drawing structures in general for the final

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_treees
Posts: 13
Joined: Fri Sep 20, 2013 3:00 am

Drawing structures in general for the final

Postby _treees » Sat Mar 15, 2014 8:14 pm

If we were to just draw line structures, do we have to specify that Hs are bonded to the carbons like shown winter final 2013 Q8B, or can we just leave that out and have the line structure look something like the figure on Final 2013 Q6A? Will I get points off if I choose to draw my structures like the latter?

704278444
Posts: 174
Joined: Fri Sep 20, 2013 3:00 am

Re: Drawing structures in general for the final

Postby 704278444 » Sat Mar 15, 2014 8:32 pm

Usually you don't need to draw H for line structure. Hs are there just for clarification.

y3chem
Posts: 172
Joined: Fri Sep 20, 2013 3:00 am

Re: Drawing structures in general for the final

Postby y3chem » Sat Mar 15, 2014 9:01 pm

I agree in with the previous post, most of the time H is implied in the line structures so we don't need to draw it out.

irisc23
Posts: 237
Joined: Sat Nov 23, 2013 3:00 am

Re: Drawing structures in general for the final

Postby irisc23 » Sat Mar 15, 2014 9:20 pm

Yep, you don't have to draw H. However, if you want to indicate how a chair conformation is staggered for every bond, for example, it would be useful to indicate the Hs. Also for a ring flip they might ask you to show that all axials become equatorials and all equatorials become axials.

Chem_Mod
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Re: Drawing structures in general for the final

Postby Chem_Mod » Wed Aug 06, 2014 9:36 am

When dealing with line structures, the hydrogen atoms are all implied. Each point or end of the line represents a carbon atom. Any other atom must be specified and written in. For example, in butene, we can count that there are 4 carbon atoms. We see that there is a double bond to give the -ene ending. And from that, to figure out the number of hydrogens attached to each carbon, we just count making sure that each carbon has 4 bonds coming off of it.

Compare the line structure with the ball and stick model to see if it makes sense of where each hydrogen attaches to.
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butene.png (1.89 KiB) Viewed 879 times
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butene

Niharika Reddy 1D
Posts: 127
Joined: Fri Sep 26, 2014 2:02 pm

Re: Drawing structures in general for the final

Postby Niharika Reddy 1D » Sat Mar 14, 2015 8:17 pm

Does leaving out the hydrogens apply for drawing chair and boat conformations as well? In past final questions, all the chair conformations have hydrogens attached or just have the axial/equatorial up/down lines drawn in, but I was wondering if it would be okay to leave them out. I think the "1 pt everything else" in the boat conformation picture attached is referring to the axial and equatorial up/down positions but I'm not sure. Thank you!
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