A condensed structural formula is same as a structural formula? Shud i draw all H.??? (1 Viewer)

lillaila

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This is soooo confusing. Some textbooks use structural formulas as eg. CH3-CH2-CH2branchblahblah-CH3
But other books draw alllllllll hydrogens.
Another book said this first one is still a structural formula but "condensed" ......it still shows adequate info (old conq. chem i think).
?????????????????????????????????
 

+:: $i[Q]u3 ::+

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they won't ask for 14 carbons
i usually draw it like a pic.. with branches and all the hydrogens attached - it makes more sens to me than all this CH3CH2Ch2CH3 nonsense.. well not nonsense.. but u get the drift.
 

Dangar

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yeah i think the CH2CH3CH2 way is a 'condensed' structural formula, but in an exam situation they're not going to ask for a huge molecule so i just do both ways. I usually need to draw the one with all the sticks first to see it properly and then just write the 'condensed' way underneath it. That way you're covered
 

Rancid Monkey

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'condensed structural formula' is CH3CH2CH3

'expanded structural formula' is
H H H
| | |
H - C - C - C - H
| | |
H H H

they *should* specify, but if they dont, be safe and do both. its not like it takes that much longer, and if they didnt say, they cant mark you wrong. most of the time if they ask you to give a formula for something they are looking for the bonds anyway.

and make sure you put H's at the end of all the bonds and dont forget the bond between the O and H in an O-H group. i have seen some teachers forget/tell students not to bother - BAD idea
 

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