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

    0
    ReputationRep:
    (Original post by otrivine)
    the structure is decoloised, (trigonal)planar molecule, the pi orbitals overlap, would include a diagram in the exam, bonding is covalent between carbon atoms, 120 .


    I have not yet started chapter 1. When I finished chapter 1 and 2 fully we revise

    Where are you up to now with your revision
    its not triagonal planar ? its hexagonal planar
    Offline

    0
    ReputationRep:
    (Original post by jordank123)
    its not triagonal planar ? its hexagonal planar
    Around each carbon atom the bond angles are 120 degrees and the bond shape is trigonal planar.

    Benzene itself is a planar molecule with 6 carbons arranged in a hexagonal shape. As you said.


    Posted from TSR Mobile
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    Around each carbon atom the bond angles are 120 degrees and the bond shape is trigonal planar.

    Benzene itself is a planar molecule with 6 carbons arranged in a hexagonal shape. As you said.


    Posted from TSR Mobile
    Exactly, because around each carbon it is 120 , so the shape is a trigonal planar
    Offline

    0
    ReputationRep:
    (Original post by otrivine)
    Exactly, because around each carbon it is 120 , so the shape is a trigonal planar
    Around each Carbon atom. Not benzene itself. You didn't specify that I think.


    Posted from TSR Mobile
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    Around each Carbon atom. Not benzene itself. You didn't specify that I think.


    Posted from TSR Mobile
    I took that from the mark scheme, and they just put , trigonal planar, award 1 mark
    Offline

    0
    ReputationRep:
    (Original post by otrivine)
    I took that from the mark scheme, and they just put , trigonal planar, award 1 mark
    They may do but it is better to know the context and put that in your answer as well. You can't learn the mark scheme and hope to get marks. :P it has the main point you need to write to get the marks. Not the actual whole complete answer.


    Posted from TSR Mobile
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    They may do but it is better to know the context and put that in your answer as well. You can't learn the mark scheme and hope to get marks. :P it has the main point you need to write to get the marks. Not the actual whole complete answer.


    Posted from TSR Mobile
    How is revision going
    Offline

    0
    ReputationRep:
    (Original post by otrivine)
    How is revision going
    Pretty much done man, only got 3 papers left to do for Tuesday.

    Wanna revise? Ask me a question.


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    Chemistry is wednesday isn't it?

    (Original post by Mus1995)
    Pretty much done man, only got 3 papers left to do for Tuesday.

    Wanna revise? Ask me a question.


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by Dr00n)
    Chemistry is wednesday isn't it?
    Yeah but I'm not doing a paper the day before so Monday** sorry is when I'm gonna have the papers done. :P


    Posted from TSR Mobile
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    Pretty much done man, only got 3 papers left to do for Tuesday.

    Wanna revise? Ask me a question.


    Posted from TSR Mobile


    Excellent, very motivated

    Okay , we start from easy ---> hard

    1) Describe why triglycerides are insoluble in water (3)
    Offline

    0
    ReputationRep:
    anyone where, or can make a guess as to where the boundaries for 90UMS lie?
    Offline

    0
    ReputationRep:
    (Original post by otrivine)
    Excellent, very motivated

    Okay , we start from easy ---> hard

    1) Describe why triglycerides are insoluble in water (3)
    Triglycerides are not soluble in water because they are non polar molecules. The long chains of fatty acids have many contact points so form many VDW forces as well as decrease the polarity of the compound. Therefore Triglycerides cannot form hydrogen bonds with water, and are insoluble.

    Q) When Bromine reacts with Phenol, what observation would you see and what product is formed?


    (Original post by rosie66)
    anyone where, or can make a guess as to where the boundaries for 90UMS lie?
    60/60 marks.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    Triglycerides are not soluble in water because they are non polar molecules. The long chains of fatty acids have many contact points so form many VDW forces as well as decrease the polarity of the compound. Therefore Triglycerides cannot form hydrogen bonds with water, and are insoluble.

    Q) When Bromine reacts with Phenol, what observation would you see and what product is formed?




    60/60 marks.
    correct,


    orange solution ---> white ppt
    Offline

    0
    ReputationRep:
    (Original post by otrivine)
    correct,


    orange solution ---> white ppt
    doesn't the bromine decolourise + white precipitate

    EDIT: oh i see you were doing the change from an orange solution, fair dos
    Offline

    1
    ReputationRep:
    (Original post by otrivine)
    correct,


    orange solution ---> white ppt
    Ohh hello , ready for the exam?

    Posted from TSR Mobile
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by D4rth)
    Ohh hello , ready for the exam?

    Posted from TSR Mobile
    Hi how are you


    I think so


    I can no longer say if I am ready for an exam , after the F325 paper in Jan 2013, not sure what to expect
    Offline

    0
    ReputationRep:
    (Original post by Mus1995)
    Triglycerides are not soluble in water because they are non polar molecules. The long chains of fatty acids have many contact points so form many VDW forces as well as decrease the polarity of the compound. Therefore Triglycerides cannot form hydrogen bonds with water, and are insoluble.

    Q) When Bromine reacts with Phenol, what observation would you see and what product is formed?




    60/60 marks.
    :/ after F325 I need as many as i can get
    Offline

    2
    ReputationRep:
    (Original post by überambitious_ox)
    Hiya,

    I read on a thread that you got 144 UMS in the F325 unit. Well done!

    Please could you provide me any tips/advice/sources that you used in order to have done so well.

    I am aiming for an A*; any advice would be appreciated.

    Thanks
    OFcourse, quite simple to get high mark on this exam:
    1) do every past paper, under exam conditions, mark critically and analyse paper after so you understand everything on it and would get full marks if you did it again.
    2)Do all the relevant legacy papers(If you want A* do all of them)
    3) do the stretch and challenge questions on the CD
    4)Do all the end of chapter questions
    dont do the things in this order though, as long as you are a normal logical person and are not stupid, you should get atleast your 135/144, A* in F325, if you do all of this
    Offline

    2
    ReputationRep:
    (Original post by Mus1995)
    Triglycerides are not soluble in water because they are non polar molecules. The long chains of fatty acids have many contact points so form many VDW forces as well as decrease the polarity of the compound. Therefore Triglycerides cannot form hydrogen bonds with water, and are insoluble.

    Q) When Bromine reacts with Phenol, what observation would you see and what product is formed?




    60/60 marks.
    brown/orange --> colourless, bromine delcolourises ,

    white precipitate 2,4,6-tribromophenol forms and 3HBr,
 
 
 
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.