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

    0
    ReputationRep:
    great , is a dative covalent bond formed in nucleophilic substitution with the nucleophile?
    Offline

    0
    ReputationRep:
    (Original post by Tikara)
    great , is a dative covalent bond formed in nucleophilic substitution with the nucleophile?
    yes it is haha just found out
    Offline

    0
    ReputationRep:
    does anybody know the formula to work out gas volumes?!
    Offline

    12
    ReputationRep:
    Scarry!
    Offline

    8
    ReputationRep:
    (Original post by buzzing22)
    does anybody know the formula to work out gas volumes?!
    Number of Moles = Volume (dm3) / 24
    Or
    Number of Moles = Volume (cm3) / 24000

    1dm3=1000cm3
    Offline

    3
    ReputationRep:
    Hi, I am studying with OCR B salters and got 1 mark from an A* in chemistry last year in triple science.
    I've done my revision and now just doing lots of past papers.
    I don't get how all of the hess's law works (enthalpy of reaction, combustion and formation) and how you construct them and what goes at the bottom.
    Also has anyone got the june 2012 paper? I can't seem to find it anywhere!
    And good luck guys !
    Offline

    2
    ReputationRep:
    (Original post by Welbeck)
    Hi, I am studying with OCR B salters and got 1 mark from an A* in chemistry last year in triple science.
    I've done my revision and now just doing lots of past papers.
    I don't get how all of the hess's law works (enthalpy of reaction, combustion and formation) and how you construct them and what goes at the bottom.
    Also has anyone got the june 2012 paper? I can't seem to find it anywhere!
    And good luck guys !
    Get the following book
    http://www.amazon.co.uk/Calculations...7384204&sr=8-1

    You can NOT ask for that paper.
    Offline

    8
    ReputationRep:
    (Original post by Welbeck)
    Hi, I am studying with OCR B salters and got 1 mark from an A* in chemistry last year in triple science.
    I've done my revision and now just doing lots of past papers.
    I don't get how all of the hess's law works (enthalpy of reaction, combustion and formation) and how you construct them and what goes at the bottom.
    Also has anyone got the june 2012 paper? I can't seem to find it anywhere!
    And good luck guys !
    Formation reaction

    Reactants → Products
    ↑ ↑
    Elements

    (One Elements arrow points to Reactants and the other to Products)

    Combustion reaction

    Reactants → Products
    ↓ ↓
    Combusted products

    (Reactant arrow and Product arrow both go to Combusted Products)

    Please request examples and more explanation of the Hess' law if this isn't clear.
    Offline

    2
    ReputationRep:
    (Original post by lilGem)
    here you are
    Is the specimen paper worth doing? Some stuff have changed like the diagram they use for mass spectroscopy in the old legacy papers
    Online

    20
    ReputationRep:
    (Original post by krisshP)
    Is the specimen paper worth doing? Some stuff have changed like the diagram they use for mass spectroscopy in the old legacy papers
    I'm yet to do it, but it probably is :cute:
    Offline

    2
    ReputationRep:
    (Original post by lilGem)
    I'm yet to do it, but it probably is :cute:
    After you do it, can you please tell me how good those old papers are and if they are woth doing?

    thanks
    Offline

    3
    ReputationRep:
    JuNe 2012 paper anD ms anyone?
    Online

    20
    ReputationRep:
    (Original post by krisshP)
    After you do it, can you please tell me how good those old papers are and if they are woth doing?

    thanks
    will do
    Offline

    2
    ReputationRep:
    (Original post by stealth_writer)
    JuNe 2012 paper anD ms anyone?
    I'm desperate for it as well. But it's too diffiucult to find
    Offline

    12
    ReputationRep:
    I'll just leave this here.
    Attached Images
  1. File Type: pdf F331-01Jun12.pdf (162.0 KB, 244 views)
    Offline

    3
    ReputationRep:
    (Original post by Coombsy)
    Formation reaction

    Reactants → Products
    ↑ ↑
    Elements

    (One Elements arrow points to Reactants and the other to Products)

    Combustion reaction

    Reactants → Products
    ↓ ↓
    Combusted products

    (Reactant arrow and Product arrow both go to Combusted Products)

    Please request examples and more explanation of the Hess' law if this isn't clear.
    Could i have a few more examples, I understand how to work out the energy change but don't get how you fill in the elements or compounds at the bottom single box in the cycle
    Thanks
    Offline

    2
    ReputationRep:
    (Original post by EstebanK0)
    I'll just leave this here.
    Mark scheme?
    Thanks
    Offline

    16
    ReputationRep:
    (Original post by EstebanK0)
    I'll just leave this here.
    You saint, thankyou! I did this and got a B a few months back, been looking for a blank script!

    (Original post by krisshP)
    Mark scheme?
    Thanks
    I've got one from my teacher but it needs some scanning up, I'll do it tomorrow if I get time.

    Just to check is it legal posting May papers that aren't available on the site etc?
    Offline

    16
    ReputationRep:
    Oh yeah, also, for people who are having trouble with Hess cycle calculations like I was, it might be worth doing it CGP-sorta style:

    1) Identify which is the direct route and which is the indirect route (arrow directions)

    2) Remember Route 1 = Route 2

    3) Sub in ΔH values in place of Route 1 = Route 2, eg ΔHr = ΔH1 + ΔH2

    4) Rearrange algebraically if necessary, i.e equation balancing

    5) Sub in the values you're given for calculation if it's required.

    Someone correct me if I'm wrong but I haven't gotten a calculation question wrong since looking at that method in the CGP salters book.
    Offline

    12
    ReputationRep:
    I'll have the MS up soon guys.
 
 
 
  • 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's your favourite Christmas sweets?
  • 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.