Turn on thread page Beta

OCR Chemistry A Exam Thread (Breadth - May 27 2016 and Depth - June 10 2016) watch

    Offline

    3
    ReputationRep:
    Liked that exam
    Here's what I remember
    Pa=4.46*10^6
    rate at 200 seconds was 0.0022
    1.85g for the mass of something (srco3?)
    percentage yield 67.4%
    metal was calcium
    z-pent-2-ene (compound A)
    last question compound C was butanoic acid?
    The major product was the one where Br went on the 2nd carbon (6 marker curly arrow method)
    Offline

    15
    ReputationRep:
    couldn't even spell Markovnikov and forgot to put H2O at the end of the oxidation question.....

    Offline

    2
    ReputationRep:
    yo mate. you good yeah?

















    CALM
    Offline

    3
    ReputationRep:
    (Original post by 456CJ)
    Did evreyone get z-pent-2-ene and 2-methyl-propanoic acid
    I got the z-pent-2-ene but I put butanoic acid?
    Offline

    16
    ReputationRep:
    From what I can remember:
    electronic configuration of magnesium 1s2 2s2 2p6 3s2
    Metal Calcium
    What happens to volume of H2 when a metal from further down is used? Lower volume as less number of moles of metal
    P4 and Cl2? P4 has more electrons so stronger London forces and stuff
    Mg and Si? Mg is metallic and Si was covalent
    Pressure? 4.something *10^6 Pa
    First 6 marker? The electrophilic substitution and the tertiary carbonation is more stable so that product is made more
    Percentage yield? 65.4 (or 64.5) %
    Second 6 marker? It had to be 2-methylpropanoic acid. The peak at 43 wouldn't work if it was butanoic acid.


    Overall an easy paper..


    Just a quick question. If I crossed out my answer from answer space and wrote the answer in additional space would that be marked the same?
    Because I redrew the enthalpy profile diagram on the back
    Offline

    1
    ReputationRep:
    (Original post by 4nonymous)
    i got the z-pent-2-ene but i put butanoic acid?
    that moment when you clearly stopped focusing and put z - pentene
    Offline

    3
    ReputationRep:
    (Original post by Nabzyvelli321)
    What did people get as the rate of reaction from the graph , did u draw a tangent and get 9*10^-4 gs-1 mot something else
    You weren't supposed to draw a tangent. A tangent is only drawn when working out the initial rate but the question asked for the rate at 200 secs so you just had to read of the graph and calculate
    I got 0.0022 (2.2*10^-3)
    Offline

    1
    ReputationRep:
    (Original post by 4nonymous)
    You weren't supposed to draw a tangent. A tangent is only drawn when working out the initial rate but the question asked for the rate at 200 secs so you just had to read of the graph and calculate
    I got 0.0022 (2.2*10^-3)
    You can draw a tangent from any point on the curve to obtain the gradient, its not just for initial.
    Offline

    16
    ReputationRep:
    (Original post by 4nonymous)
    You weren't supposed to draw a tangent. A tangent is only drawn when working out the initial rate but the question asked for the rate at 200 secs so you just had to read of the graph and calculate
    I got 0.0022 (2.2*10^-3)
    It was a curve so you had to draw a tangent
    Offline

    3
    ReputationRep:
    (Original post by asinghj)
    From what I can remember:
    electronic configuration of magnesium 1s2 2s2 2p6 3s2
    Metal Calcium
    What happens to volume of H2 when a metal from further down is used? Lower volume as less number of moles of metal
    P4 and Cl2? P4 has more electrons so stronger London forces and stuff
    Mg and Si? Mg is metallic and Si was covalent
    Pressure? 4.something *10^6 Pa
    First 6 marker? The electrophilic substitution and the tertiary carbonation is more stable so that product is made more
    Percentage yield? 65.4 (or 64.5) %
    Second 6 marker? It had to be 2-methylpropanoic acid. The peak at 43 wouldn't work if it was butanoic acid.


    Overall an easy paper..


    Just a quick question. If I crossed out my answer from answer space and wrote the answer in additional space would that be marked the same?
    Because I redrew the enthalpy profile diagram on the back
    Yh it would. Also I think for yield it was 67.4%
    As for the last question 43 peak does work with butanoic acid because its (CH3CH2CH2)+ ? Although I aint sure
    Offline

    16
    ReputationRep:
    Unofficial mark scheme?
    Offline

    8
    ReputationRep:
    (Original post by asinghj)
    From what I can remember:
    electronic configuration of magnesium 1s2 2s2 2p6 3s2
    Metal Calcium
    What happens to volume of H2 when a metal from further down is used? Lower volume as less number of moles of metal
    P4 and Cl2? P4 has more electrons so stronger London forces and stuff
    Mg and Si? Mg is metallic and Si was covalent
    Pressure? 4.something *10^6 Pa
    First 6 marker? The electrophilic substitution and the tertiary carbonation is more stable so that product is made more
    Percentage yield? 65.4 (or 64.5) %
    Second 6 marker? It had to be 2-methylpropanoic acid. The peak at 43 wouldn't work if it was butanoic acid.


    Overall an easy paper..


    Just a quick question. If I crossed out my answer from answer space and wrote the answer in additional space would that be marked the same?
    Because I redrew the enthalpy profile diagram on the back
    Mg was ionic I swear, it forms ionic bonds, not metllaic bonds.
    Offline

    1
    ReputationRep:
    (Original post by Awsomedude)
    Mg was ionic I swear, it forms ionic bonds, not metllaic bonds.
    Ionic is between a metal and non-metal, mg is just a metal
    Offline

    3
    ReputationRep:
    (Original post by asinghj)
    It was a curve so you had to draw a tangent
    (Original post by Tyler213)
    You can draw a tangent from any point on the curve to obtain the gradient, its not just for initial.
    You didn't have to because it asked for it at a specific point so you can use that point to work it out. That's how we do it biology at least?
    • Thread Starter
    Offline

    14
    ReputationRep:
    Please tell me the last one about the mass spec question was Butanoic acid


    Posted from TSR Mobile
    Offline

    1
    ReputationRep:
    Yield was 67.4%
    Offline

    3
    ReputationRep:
    (Original post by Awsomedude)
    Mg was ionic I swear, it forms ionic bonds, not metllaic bonds.
    Its metallic, ionic is between + and - ions metallic is between the + mg2+ ion and the delocalised electrons
    Offline

    3
    ReputationRep:
    Wasn't it 67.5%
    Offline

    16
    ReputationRep:
    (Original post by 4nonymous)
    You didn't have to because it asked for it at a specific point so you can use that point to work it out. That's how we do it biology at least?
    Check chemistry textbook page 148
    Offline

    9
    ReputationRep:
    (Original post by 4nonymous)
    You didn't have to because it asked for it at a specific point so you can use that point to work it out. That's how we do it biology at least?
    it was 'in the first 200 secs' not at 200 secs I think
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: June 27, 2017
The home of Results and Clearing

1,376

people online now

1,567,000

students helped last year

University open days

  1. Bournemouth University
    Clearing Open Day Undergraduate
    Wed, 22 Aug '18
  2. University of Buckingham
    Postgraduate Open Evening Postgraduate
    Thu, 23 Aug '18
  3. University of Glasgow
    All Subjects Undergraduate
    Tue, 28 Aug '18
Poll
How are you feeling about GCSE results day?

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.