The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

Naming substances

I was just wondering if anyone could help. I am trying to find the IUPAC name of this carboxylic acid with the structural formula (CH3)2CH(OH)CH2COOH - I've tried drawing out the displayed formula but keep getting confused as to where the OH would go. If anyone could help, I'd be extremely grateful! :smile:
Original post by Lydia.Mx
I was just wondering if anyone could help. I am trying to find the IUPAC name of this carboxylic acid with the structural formula (CH3)2CH(OH)CH2COOH - I've tried drawing out the displayed formula but keep getting confused as to where the OH would go. If anyone could help, I'd be extremely grateful! :smile:


The if there is an OH group in the molecule as you say, then the formula should be (CH3)2C(OH)CH2COOH (not (CH3)2CH(OH)CH2COOH) as that carbon would have 5 things bonded to it, which isn't right). I've underlined the groups bonded to the bolded C for clarity. That OH is bonded to the C to the left of it. I think that should help somewhat :smile:
(edited 5 years ago)
Reply 2
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by Professor L
The if there is an OH group in the molecule as you say, then the formula should be (CH3)2C(OH)CH2COOH (not (CH3)2CH(OH)CH2COOH) as that carbon would have 5 things bonded to it, which isn't right). I've underlined the groups bonded to the bolded C for clarity. That OH is bonded to the C to the left of it. I think that should help somewhat :smile:

Thank you so much - this is extremely helpful! It was written on a homework sheet I was given & I was thinking it was werid as carbon can only 4 atoms bonded to it so that would make a lot more sense, thank you :smile:
I think that would make it 3-hydroxy-4-methylpentanoic acid :smile:
(edited 5 years ago)
Original post by Professor L
The if there is an OH group in the molecule as you say, then the formula should be (CH3)2C(OH)CH2COOH (not (CH3)2CH(OH)CH2COOH) as that carbon would have 5 things bonded to it, which isn't right). I've underlined the groups bonded to the bolded C for clarity. That OH is bonded to the C to the left of it. I think that should help somewhat :smile:

would it be 1,1-methyl,2hydroxyl butanoic acid . im just starting as nomenclature so i didint know what to do about the hydroxyl group ?
Reply 4
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
would it be 1,1-methyl,2hydroxyl butanoic acid . im just starting as nomenclature so i didint know what to do about the hydroxyl group ?

That is what threw me! I've literally sat trying to work it out for about an hour! I just worked it out to be 3-hydroxy-4-methylpentanoic acid I think (I might be wrong) but I think you would count the other way to ensure you have the group with the highest priority (carboxylic acid) as 1 & then the hydroxyl group would be on its own carbon next to the methyl groups. It honestly confuses me so much haha - thanks so much for your help though - I really appreciate it!! :smile:
Original post by Lydia.Mx
That is what threw me! I've literally sat trying to work it out for about an hour! I just worked it out to be 3-hydroxy-4-methylpentanoic acid I think (I might be wrong) but I think you would count the other way to ensure you have the group with the highest priority (carboxylic acid) as 1 & then the hydroxyl group would be on its own carbon next to the methyl groups. It honestly confuses me so much haha - thanks so much for your help though - I really appreciate it!! :smile:

oh yeah forgot about that argh so many rules haha .
Reply 6
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
oh yeah forgot about that argh so many rules haha .

Tell me about it haha!
Original post by Lydia.Mx
Tell me about it haha!

if this is homework, can you let me know the answer when you find out ?
thanks :smile:
Reply 8
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
if this is homework, can you let me know the answer when you find out ?
thanks :smile:

Yes of course, its due Wednesday & we usually go over it in the lesson so I'll let you know then :smile:
Original post by Lydia.Mx
Thank you so much - this is extremely helpful! It was written on a homework sheet I was given & I was thinking it was werid as carbon can only 4 atoms bonded to it so that would make a lot more sense, thank you :smile:
I think that would make it 3-hydroxy-4-methylpentanoic acid :smile:


You nearly got it! You have to look at the longest possible unbranching carbon chain in the molecule, which is 4 carbons long in this molecule, so it would be a butanoic acid. Then you have both the OH and the methyl on carbon 3.
Reply 10
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by Professor L
You nearly got it! You have to look at the longest possible unbranching carbon chain in the molecule, which is 4 carbons long in this molecule, so it would be a butanoic acid. Then you have both the OH and the methyl on carbon 3.

Ahh no! Okay great, that makes sense - thanks so much for your help, I really appreciate it! :smile:
Original post by Lydia.Mx
Ahh no! Okay great, that makes sense - thanks so much for your help, I really appreciate it! :smile:

Are you in year 12?
Reply 12
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
Are you in year 12?

yes I am, are you?
Original post by Lydia.Mx
yes I am, are you?

Yeah
Reply 14
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
Yeah

cool! What other subjects are you taking?
Original post by Lydia.Mx
Ahh no! Okay great, that makes sense - thanks so much for your help, I really appreciate it! :smile:


You're welcome! :biggrin:
Original post by Lydia.Mx
cool! What other subjects are you taking?

Biology and psychology
How about you?
Reply 17
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
Biology and psychology
How about you?

Oh cool! Biology, geography and core maths :smile:
Original post by Lydia.Mx
Oh cool! Biology, geography and core maths :smile:

You do four. Wow. Good luck.
Are you planning on dropping one after a year or doing 4 ?
Reply 19
Avatar for Lydia.Mx
Lydia.Mx
OP
14
Original post by emilysandres
You do four. Wow. Good luck.
Are you planning on dropping one after a year or doing 4 ?

Haha thanks, its not as bad as it sounds - At my school we have electives which we have to take which are one year courses so either work experince, volunteering, EPQ, core maths or further maths & core maths is basically just maths but more problem solving type things so not as hard as A level maths but it just helps with the maths in the sciences & is equivalent to an As grade & the exam is in May so I won't be doing that next year :smile:

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you