Turn on thread page Beta
    Offline

    0
    ReputationRep:
    (Original post by AmS)
    Yep they took clays off the syllabus starting from the Jan chemistry by design exam. im pretty sure because the syllabus does not mention anything about clays in the aspects of agriculture section.....but who knows they mite jus throw in a question on it cos u know wat the salters people are like!!lol
    Oh I see!! I absolutely panicked when I saw a question on a past paper "Using your knowledge of the structure of clays....." so I looked it up in storylines and made notes but still didn't understand. I'm so glad that's been taken off! I will never in a million years learn all these reaction conditions! x
    Offline

    2
    ReputationRep:
    Clays been taken off?!?!

    Offline

    0
    ReputationRep:
    (Original post by Ramaya)
    Clays been taken off?!?!

    Yup. Happy days
    • Thread Starter
    Offline

    0
    ReputationRep:
    is it just me or any1 finiding the later papers (04/05's) slightly easier then the older ones (02's) ?
    Offline

    1
    ReputationRep:
    Am doing the synoptic salters chemistry tomorrow...

    In past exam questions, etc, they only ever seem to ask about calculating the pH of strong or weak acids.. which is something I can actually do! (be amazed, I can't do most chemistry calculations...I see numbers and hide) Will they ever ask us about calculating the pH of strong or weak alkalis? Don't you need to know Kw of water or something along those lines? I know theres something anyway... I havn't actually seen any exam questions on this however, only the acidic pH calculations. Is it worth my while trying to learn the alkali calculations?
    Offline

    0
    ReputationRep:
    (Original post by ainat87)
    Am doing the synoptic salters chemistry tomorrow...

    In past exam questions, etc, they only ever seem to ask about calculating the pH of strong or weak acids.. which is something I can actually do! (be amazed, I can't do most chemistry calculations...I see numbers and hide) Will they ever ask us about calculating the pH of strong or weak alkalis? Don't you need to know Kw of water or something along those lines? I know theres something anyway... I havn't actually seen any exam questions on this however, only the acidic pH calculations. Is it worth my while trying to learn the alkali calculations?
    Yeah you say

    Kw = [H+ ] x [OH- ]

    Since you knwo the conc of OH- and Kw, you can work out the conc of H+ ions and so work out the pH of the solution!
    Offline

    0
    ReputationRep:
    (Original post by ainat87)
    Am doing the synoptic salters chemistry tomorrow...

    In past exam questions, etc, they only ever seem to ask about calculating the pH of strong or weak acids.. which is something I can actually do! (be amazed, I can't do most chemistry calculations...I see numbers and hide) Will they ever ask us about calculating the pH of strong or weak alkalis? Don't you need to know Kw of water or something along those lines? I know theres something anyway... I havn't actually seen any exam questions on this however, only the acidic pH calculations. Is it worth my while trying to learn the alkali calculations?
    jus remember Kw = [H+(aq)][OH-(aq)] which is the ionic product of water. then you'll probably be given the value of Kw and the concentration of the [OH-] which you can substitute into the above equation. That gives you [H+], which u can then calculate the pH from by using -log[H+]! i think thats rite anyway!lol
    Offline

    0
    ReputationRep:
    (Original post by AmS)
    jus remember Kw = [H+(aq)][OH-(aq)] which is the ionic product of water. then you'll probably be given the value of Kw and the concentration of the [OH-] which you can substitute into the above equation. That gives you [H+], which u can then calculate the pH from by using -log[H+]! i think thats rite anyway!lol
    you aren't given the value for Kw. You are expected to know that!
    Offline

    0
    ReputationRep:
    (Original post by roochis)
    you aren't given the value for Kw. You are expected to know that!
    I know you have 2 be able 2 explain the significance of the ionic product of water but i would have thought that in a calculation question they jus giv u it in the question 10^-14......oh well guess not jus another little thing 2 remember then!lol
    Offline

    17
    ReputationRep:
    I'm sure i've done one paper that's given it...
    Offline

    0
    ReputationRep:
    (Original post by Bekaboo)
    I'm sure i've done one paper that's given it...
    cool, thanks! i thought they usually would.
    Offline

    1
    ReputationRep:
    ok. cheers. I can do the acidic ones, I spose I should get learning these alkali ones...

    What exactly do we need to know about buffer solutions? Asides from what they are of course. :p:
    Offline

    17
    ReputationRep:
    Umm you need to be able to work out Ka (do i mean Ka? Or Kc maybe? Damn i'm confused )

    And show how the pH is contained
    Offline

    0
    ReputationRep:
    So is everyone ready for 2moro? I feel like i know quite a lot, but not all the things that i need 2 know, there seems 2 be so much!! But anyways its my last exam, so can go completely wild straight after!lol
    Offline

    17
    ReputationRep:
    nooooooooooooooooooooooooooooo

    It's my last exam though thank goodness!!

    Stuff is finally starting to come together

    Gonna go learn reaction mechanisms in a minute -there are so many!! :eek:
    Offline

    1
    ReputationRep:
    There aren't MILLIONS!

    Need to know HCN nucleophillic attack on the carbonyl group of a Ketone and Aldehyde... And you also need to have a fair idea of the Benzene electrophillic subsitutions.

    I'm not sure there is anything more specific beyond that!
    • Thread Starter
    Offline

    0
    ReputationRep:
    any1 got any predictions on big mark questions judging from past papers?
    Offline

    17
    ReputationRep:
    Haha you're having a laugh we have to know all the reaction conditions for
    Hydrogenation, Bromination, electrophilic addition of HBr, addition polymerisation and addition of CN for alkenes
    The two ways to make alcohols from halogenoalkanes, as well as addition of C=N and conversion to amine

    That's one of my two pages
    Then there's reactions of alcohols, aldehydes, ketones and amines :eek:
    Offline

    0
    ReputationRep:
    revision isn't going in! Argh! I bet tomorrow will be really hard if it is anything like thursday :eek:
    Offline

    0
    ReputationRep:
    The big mark questions do tend to vary, although there is often one on explaining why we see things coloured, and sometimes extending that to why compound is coloured and another not. There're also often a fair few marks for knowing and applying Le Chatalier's Principle.

    I actually think this is one of the nicer synoptic papers I'm doing - certainly nice than AQA Physics. Just because it has lots of low mark questions, so if you don't know something like some reaction conditions, you don't lose much, and because the calculations are often independent and so don't go wrong by use of an incorrect previous answer.

    For buffers you just need to know what they are, why they work (Le Chatalier again) and how to calculate their average pH for the Ka equation.

    For reaction conditions, try http://www.york.ac.uk/org/seg/salter...cexercise1.doc. This link has printable sheets to fill in for them, and the answers, and loads of other stuff I've not even really looked at.
 
 
 
The home of Results and Clearing

3,829

people online now

1,567,000

students helped last year

University open days

  1. Bournemouth University
    Clearing Open Day Undergraduate
    Fri, 17 Aug '18
  2. University of Bolton
    Undergraduate Open Day Undergraduate
    Fri, 17 Aug '18
  3. Bishop Grosseteste University
    All Courses Undergraduate
    Fri, 17 Aug '18
Poll
A-level students - how do you feel about your results?

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

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