Hey there Sign in to join this conversationNew here? Join for free

AS chem question

Announcements Posted on
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    http://tringscience.pbworks.com/f/f3...nt+june+07.pdf

    q3 a (i).


    The mark scheme says that only A is a hydrocarbon... why aren't they all?
    It also says B isn't an ether group, but surely it is because of the oxygen atom on the end?
    • 0 followers
    Offline

    ReputationRep:
    A hydrocarbon only contains hydrogen and carbon so the other two aren't hydrocarbons because they also contain oxygen.
    B is an aldehyde not an ether because it has a HC=O group on the end. An ether must have an oxygen singly bonded to 2 carbons.
    • 28 followers
    Offline

    ReputationRep:
    (Original post by lollage123)
    http://tringscience.pbworks.com/f/f3...nt+june+07.pdf

    q3 a (i).


    The mark scheme says that only A is a hydrocarbon... why aren't they all?
    It also says B isn't an ether group, but surely it is because of the oxygen atom on the end?
    A hydrocarbon is a molecule which contains only atoms of hydrogen and carbon. Molecules B and C contain oxygen atoms as well as hydrogen and carbon atoms, and thus are not hydrocarbons.

    An ether group is R-O-R', like the one in 5-membered ring in molecule C. B is not an ether group, as it is only connected to 1 carbon atom via a C=O bond. This molecule is actually an aldehyde.

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?

    this is what you'll be called on TSR

  2. this can't be left blank
    this email is already registered. Forgotten your password?

    never shared and never spammed

  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide the button to the right to create your account

    Slide to join now Processing…

Updated: April 15, 2012
New on TSR

What are your A-level predictions?

Join our AS and A2 results day chat thread

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.