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

    0
    ReputationRep:
    (Original post by ManPowa)
    What did you guys put for the Reaction? How the concentration could be found?
    it was 3 marks, split into method, what measured and cant remember the fiirst one..
    I guessed that 1 saying iodine clock method lol, think it's wrong though.
    Offline

    0
    ReputationRep:
    (Original post by ManPowa)
    What did you guys put for the Reaction? How the concentration could be found?
    it was 3 marks, split into method, what measured and cant remember the fiirst one..
    Oh I know what your talking about! I proper made that one up :s:

    I wrote something about colorimetry I think.
    Offline

    2
    ReputationRep:
    (Original post by BazzaMan)
    I guessed that 1 saying iodine clock method lol, think it's wrong though.
    I just put Absorbtion as the thing measured, substance measured as Iodide Ions and Colorimetry as the method, which is basically iodine clock anyway
    Offline

    1
    ReputationRep:
    Ohhhh for the reaction one.

    I put measure how fast H+ ions are used up with PH METER?!?!?! IS this right!?!
    Offline

    2
    ReputationRep:
    (Original post by hidden_desire)
    Oh I know what your talking about! I proper made that one up :s:

    I wrote something about colorimetry I think.
    I said this too!! Because of the colour of the bromide ions you are able to follow the rate by colorimetry
    Offline

    2
    ReputationRep:
    (Original post by Darthdevidem)
    Ohhhh for the reaction one.

    I put measure how fast H+ ions are used up with PH METER?!?!?! IS this right!?!
    Interestingly I'm doing a similar experiment as part of my coursework, except I'm titrating it to find the concentration of the H+ ions. Hopefully the mark scheme won't be ridiculously pedantic
    Offline

    2
    ReputationRep:
    (Original post by Darthdevidem)
    Ohhhh for the reaction one.

    I put measure how fast H+ ions are used up with PH METER?!?!?! IS this right!?!
    Thats what i wrote aswell.. as H+ iona are present, you calculate the change in PH of the reaction using a PH METER.

    But everyone else i asked in my college. they said something to do with iodine..


    HELP...... :confused::confused:
    Offline

    0
    ReputationRep:
    i put how much h20 was produced in a given time...........
    did they specify not to use water? oh dear.
    Offline

    2
    ReputationRep:
    I said work out the volume of I2 produced in the reaction by titrating samples against thiosulphate ions.
    Offline

    0
    ReputationRep:
    (Original post by ManPowa)
    What did you guys put for the Reaction? How the concentration could be found?
    it was 3 marks, split into method, what measured and cant remember the fiirst one..
    you can put stuff about acidity (H+) ions or that sodium thiosulphate titration thing with starch indicator i think, as i think i remember there being iodine involved. and H+ would be measured with a pH probe.
    Offline

    13
    ReputationRep:
    I put:

    pH
    H+ ions
    pH meter
    Offline

    0
    ReputationRep:
    (Original post by ManPowa)
    What did you guys put for the Reaction? How the concentration could be found?
    it was 3 marks, split into method, what measured and cant remember the fiirst one..
    i put you could add startch indicator and follow the reaction in a colorimeter...because it will slowly turn black as the iodine is produced.
    Offline

    0
    ReputationRep:
    (Original post by brendan.)
    Wow, really? I thought the rest of it was generally okay though, so I think Q7 was really only my complete fail, haa.
    How did you find chem?
    Haha, well.. I did go into the exam not knowing much, so if I get anything above a D, I'd be really happy tbh Chem, I thought was alright actually.. Some bits made me think WTF?! But overall it was a good paper How did you find it?
    Offline

    1
    ReputationRep:
    (Original post by ManPowa)
    Thats what i wrote aswell.. as H+ iona are present, you calculate the change in PH of the reaction using a PH METER.

    But everyone else i asked in my college. they said something to do with iodine..


    HELP...... :confused::confused:
    Well for these questions I think there's never just 1 answer specifically (thats what the revision guide says anyway).

    Maybe we used the more innovative method and will hopefully get extra marks hehe (oh do I need extra marks in this paper!)
    Offline

    0
    ReputationRep:
    What did you guys put for the question where it asked for a reagent or something like that that would turn caboxylic acids to carboxylate ions? I put sodium hydroxide solution. Is this right?:confused:
    Offline

    14
    ReputationRep:
    (Original post by ManPowa)
    Thats what i wrote aswell.. as H+ iona are present, you calculate the change in PH of the reaction using a PH METER.

    But everyone else i asked in my college. they said something to do with iodine..


    HELP...... :confused::confused:
    This is correct don't worry, H2O was produced so there would be an appreciable AND measurable change in pH.
    Offline

    14
    ReputationRep:
    (Original post by zahre)
    What did you guys put for the question where it asked for a reagent or something like that that would turn caboxylic acids to carboxylate ions? I put sodium hydroxide solution. Is this right?:confused:
    Any reference to a strong Base DILUTED in water would be correct.
    E.g. Dilute NaOH
    Offline

    2
    ReputationRep:
    (Original post by Kartace)
    Any reference to a strong Base DILUTED in water would be correct.
    E.g. Dilute NaOH
    thats not correct.. the right answer is water.. H20.

    because:

    acid + water = carboxylate ion + oxonium ion.
    Offline

    0
    ReputationRep:
    (Original post by Kartace)
    Any reference to a strong Base DILUTED in water would be correct.
    E.g. Dilute NaOH
    Oh crap. Didnt include the diluted part. Is it wrong to just say sodium hydroxide?:mad:
    Offline

    14
    ReputationRep:
    (Original post by ManPowa)
    thats not correct.. the right answer is water.. H20.

    because:

    acid + water = carboxylate ion + oxonium ion.
    the water comes from the dilution, the OH- ions are catalysts

    Dilute alkali hydrolysis produces Carboxylate ion and NH3
    If it were a dilute acid hydrolysis the an ammonium ion NH4+ and carboxcylic acid would be produced
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What newspaper do you read/prefer?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.