OCR Chemistry A 2016 unofficial mark scheme 27/05/16

Announcements Posted on
How helpful is our apprenticeship zone? Have your say with our short survey 02-12-2016
    Offline

    3
    ReputationRep:
    (Original post by SGHD26716)
    I know this is unlikely that you remember this but do you know the equation and moles. I just can't remember the answer I wrote if it was right or not.
    dk if this is the right question but
    2:1 ratio
    0.075 mol
    so 0.15 mol


    guys I remember some multi choice questions i doubt anyone cares or not, either way:

    - shape around carbon atoms in graphene
    - iodoalkane hydrolysing fastest
    - calculating enthalpy of formation using enthalpy of combustion - i got -129
    - which skeletal formula oxidised to a ketone (near the end) - B??
    - which molecule was non-polar - E 2,3but-2-ene

    if anyone remembers them pls say there was 20.
    Offline

    1
    ReputationRep:
    How did you do the enthalpy change of reaction question
    Offline

    1
    ReputationRep:
    (Original post by Bosssman)
    Empirical formula with water of crystallisation: Cr3Cl • 6H2O
    It was CrCl3•6H2O, wrong way round!
    Offline

    1
    ReputationRep:
    Have a feeling the grade boundaries are going to be pretty high as the paper was decent.. Next one is going to be a lot more technical. How did everyone find the one today
    Offline

    1
    ReputationRep:
    (Original post by tamoni4)
    You cannot use Br2 because you will make a dihaloalkane and you cannot make an alcohol from dihaloalkane. You had to use HBr to make haloalkane and then NaOH to make alcohol.
    It had two OH groups so you had to use Br2 or Cl2
    Offline

    2
    (Original post by lauren1346)
    It was CrCl3•6H2O, wrong way round!
    I got this but I didn't even put the dot in between😒 they're probably going to mark it wrong


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    What did you put for the iodoalkabe hydrolysing the fastest.
    alkaline.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by medicapplicant)
    What did you put for the iodoalkabe hydrolysing the fastest.
    alkaline.
    C-I bond requires less energy to break
    Offline

    1
    ReputationRep:
    (Original post by MsDanderson)
    I got this but I didn't even put the dot in between😒 they're probably going to mark it wrong


    Posted from TSR Mobile
    Based off of the new mark schemes they are very... anal. So sadly I think you'll drop 1 mark.
    Offline

    2
    ReputationRep:
    (Original post by Bosssman)
    C-I bond requires less energy to break
    Alright good and I swear that water of crystallisation question answer was CrCl3.6H20 like someone above
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by medicapplicant)
    Alright good and I swear that water of crystallisation question answer was CrCl3.6H20 like someone above
    Maybe, there was a 3 somewhere and the other element was 1 and the water was 6
    Offline

    2
    ReputationRep:
    (Original post by Bosssman)
    I don't have a copy of the exam, literally just walked out of the exam room 30 mins ago haha
    what calc do you have
    Offline

    1
    ReputationRep:
    (Original post by Bosssman)
    Maybe, there was a 3 somewhere and the other element was 1 and the water was 6
    ya it was i think CrCl3 . 6H20
    Offline

    3
    ReputationRep:
    (Original post by MsDanderson)
    I got this but I didn't even put the dot in between😒 they're probably going to mark it wrong


    Posted from TSR Mobile
    They did explicitly say to 'show clearly the water of crystallisation'
    Offline

    2
    ReputationRep:
    (Original post by connorhill)
    Anyone tell me how they got 58 or whatever it was for the enthalpy change, I got the 4... KJ then I think I divided it by like 0.174 to get 19?
    I got -19.5 ... Didn't you have to times the number of moles by three?
    Offline

    1
    ReputationRep:
    Hated that paper! Wasn't the 10% more-find concentration question 2 marks not 3. How many marks do you think you lost?
    Offline

    3
    ReputationRep:
    (Original post by alkaline.)
    dk if this is the right question but
    2:1 ratio
    0.075 mol
    so 0.15 mol


    guys I remember some multi choice questions i doubt anyone cares or not, either way:

    - shape around carbon atoms in graphene
    - iodoalkane hydrolysing fastest
    - calculating enthalpy of formation using enthalpy of combustion - i got -129
    - which skeletal formula oxidised to a ketone (near the end) - B??
    - which molecule was non-polar - E 2,3but-2-ene

    if anyone remembers them pls say there was 20.
    I think there are always 20 marks available in MCQ. Shape around graphemes, I put tetrahedral.
    Offline

    3
    ReputationRep:
    (Original post by SGHD26716)
    I think there are always 20 marks available in MCQ. Shape around graphemes, I put tetrahedral.
    I thought it was tetrahedral bc that's just generally what it is in alkanes
    Ive realised now that in graphene each carbon is bonded to 3 other carbons and theres one free floating or something so idk if it's trigonal planar ... ://

    upon googling: http://virtuallaboratory.colorado.ed...ter3txt-3.html
    "This geometry is called trigonal planar and the C–C–C bond angle is 120°"

    fuc.
    Offline

    1
    ReputationRep:
    (Original post by Bosssman)
    Maybe, there was a 3 somewhere and the other element was 1 and the water was 6
    I googled both, Cr3Cl.6H2O doesn't seem to be a thing, whereas CrCl3.... does.
    Offline

    2
    ReputationRep:
    I think i got a B on the paper and not quite the A grade. What marks will i need in the next paper (Depth) to get an overall A grade for AS Chemistry.
 
 
 
Write a reply… Reply
Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: November 22, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR
Poll
Would you rather have...?
Useful resources
Study resources

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.