Join TSR now and get all your revision questions answeredSign up now
    Offline

    0
    ReputationRep:
    I reckon there will be a big combined techniques question at the end. Hopefully there is
    Offline

    1
    ReputationRep:
    (Original post by D4rth)
    If its more soluble in the stationary phase it has a longer time as its harder for the mobile phase to carry it through the column.
    It depends on what the greater solubility is in, if its more soluble in the mobile phase retention time is shorter.

    Posted from TSR Mobile
    thanks could you explain for both tlc and gas
    is tlc always adsorption?
    in tlc if its more soluble/adsorpable(?) in stationary phase will rf value be greater, same with gas chromotography retention time greater
    Offline

    0
    ReputationRep:
    (Original post by thers)
    One more


    How many chiral centres in this molecule? [1]
    Is it 1?

    Edit: I saw your answer
    Offline

    13
    ReputationRep:
    (Original post by thers)
    One more


    How many chiral centres in this molecule? [1]
    is there 0?
    Offline

    1
    ReputationRep:
    (Original post by otrivine)
    why do you have blue and red? do they mean separate dont get why they are coloured
    Lol I just randomly chose this molecule from google images - I don't know why they are coloured (probably to show the distinct functional groups.
    Offline

    0
    ReputationRep:
    Can anyone help me with this?
    Describe and explain the increased use of esters of fatty acids as biodiesel.
    Offline

    1
    ReputationRep:
    (Original post by thers)
    Answer

    Spoiler:
    Show

    0 chiral centres
    If you said 2, you fell into my trap.
    Why is it 0?

    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by D4rth)
    NH and OH always appear as singlets.

    Watch this video
    https://www.youtube.com/watch?v=k6F_...e_gdata_player

    Posted from TSR Mobile
    that video is amazing but how does he know how big to make the peaks when he draws them? Thanks.
    Offline

    1
    ReputationRep:
    (Original post by AFC_123456789)
    that video is amazing but how does he know how big to make the peaks when he draws them? Thanks.
    They're just relative, the peak with 3 protons in the environment will be bigger than the peak with 2 protons in the environment. I don't think the examiners will be that picky though.

    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    Any predictions on what might come up
    Offline

    1
    ReputationRep:
    (Original post by Varsh05)
    Can anyone help me with this?
    Describe and explain the increased use of esters of fatty acids as biodiesel.
    Biodegradable - breakdown doesn't emit harmful gases.
    Made form plants so carbon neutral/environmentally friendly.

    How many marks is it?
    Offline

    0
    ReputationRep:
    (Original post by D4rth)
    I assume you mean Jan 13? Its been posted many times, check the last few pages, it'll be in an attachment.

    Posted from TSR Mobile
    yeah my bad!! thanks
    Offline

    1
    ReputationRep:
    (Original post by D4rth)
    Why is it 0?

    Posted from TSR Mobile
    Lets look at the carbon with the NH2 group sticking out of it. The groups coming out are -NH2, -H, -CH2CH2CHOH and -CH2CH2CHOH. Same can be said for the carbon with OH sticking out but swap the OH with NH2. So those 2 carbons are not chiral
    Offline

    0
    ReputationRep:
    (Original post by _HabibaH_)
    Biodegradable - breakdown doesn't emit harmful gases.
    Made form plants so carbon neutral/environmentally friendly.

    How many marks is it?
    It's just a question from the spec that we're supposed to know.
    Offline

    1
    ReputationRep:
    Just did Jan 13 - scored 85 and in Jan I just scraped a C. I don't know whether to be crazy happy or crazy confused.
    Offline

    0
    ReputationRep:
    Just me or is it anyone else's last exam and I've lost all motivation

    HELP
    Offline

    0
    ReputationRep:
    (Original post by _HabibaH_)
    Just did Jan 13 - scored 85 and in Jan I just scraped a C. I don't know whether to be crazy happy or crazy confused.
    Is that 85 UMS lol?
    Offline

    1
    ReputationRep:
    (Original post by thers)
    Lets look at the carbon with the NH2 group sticking out of it. The groups coming out are -NH2, -H, -CH2CH2CHOH and -CH2CH2CHOH. Same can be said for the carbon with OH sticking out but swap the OH with NH2. So those 2 carbons are not chiral
    Oh dammit, I'm used to more complex molecules where the things on either side of the chain are completely different. Thanks

    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by _HabibaH_)
    Just did Jan 13 - scored 85 and in Jan I just scraped a C. I don't know whether to be crazy happy or crazy confused.
    Jan 13 was a ***** of a paper did it for our mock got a C or something dismal
    Offline

    0
    ReputationRep:
    (Original post by livvy965)
    Just me or is it anyone else's last exam and I've lost all motivation

    HELP
    It's mine as well and I had maths this morning and really just can't concentrate. I'm downing coffee and coke trying to get as much caffeine as possible
 
 
 
Poll
If you won £30,000, which of these would you spend it on?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

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