Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    Offline

    0
    ReputationRep:
    Can someone give me the "mark scheme style" definitions for initiation, propagation and termination (I understand them, just don't wanna lose silly marks for missing out key phrases if they do come up)
    Offline

    11
    ReputationRep:
    (Original post by Branny101)
    Ahh awesome, thanks for the link

    Posted from TSR Mobile
    no problem!
    Offline

    11
    ReputationRep:
    (Original post by ActaNonVerba)
    Can someone give me the "mark scheme style" definitions for initiation, propagation and termination (I understand them, just don't wanna lose silly marks for missing out key phrases if they do come up)
    I'll try
    Initiation-radical produced from a non-radical
    Propagation- radical replaced by another with a radical on both sides of equation
    Termination-radical used up to produce non-radicals
    Offline

    2
    ReputationRep:
    Hi does anyone know where I could find the grade boundaries for the legacy papers?
    Offline

    9
    ReputationRep:
    hey guys, really dreading this exam as i gather most of you are -_-
    can someone please help me on a q from the jan 2010 paper?
    here's the question:

    1f. Scientists monitor the composition of the Earth's atmosphere. They have found that the concentration of carbon dioxide in dry, unpolluted tropospheric air has increased from 300ppm to around 380ppm between 1900 and the present day.
    i) Taking the present day value to be 380ppm, calculate the increase in the percentage of carbon dioxide in the air between 1900 and the present day.

    I converted the values into percentages so,
    380/100000=0.0038% and 300/100000=0.0030%
    so the difference between these values is 0.008, therefore 0.008/0.003

    but according to the mark scheme its meant to be 0.008/8*10^ -3.
    Any help would be appreciated, its only one mark but its really frustrating me. Thanks in advance
    Offline

    9
    ReputationRep:
    (Original post by hen4r)
    Hi does anyone know where I could find the grade boundaries for the legacy papers?
    are there any ones you wanted in particular? cos we got them on the school VLE, i could download the one you wanted onto here if you want?
    • Peer Support Volunteers
    • Study Helper
    Offline

    19
    Peer Support Volunteers
    Study Helper
    (Original post by Zarah01)
    hey guys, really dreading this exam as i gather most of you are -_-
    can someone please help me on a q from the jan 2010 paper?
    here's the question:

    1f. Scientists monitor the composition of the Earth's atmosphere. They have found that the concentration of carbon dioxide in dry, unpolluted tropospheric air has increased from 300ppm to around 380ppm between 1900 and the present day.
    i) Taking the present day value to be 380ppm, calculate the increase in the percentage of carbon dioxide in the air between 1900 and the present day.

    I converted the values into percentages so,
    380/100000=0.0038% and 300/100000=0.0030%
    so the difference between these values is 0.008, therefore 0.008/0.003

    but according to the mark scheme its meant to be 0.008/8*10^ -3.
    Any help would be appreciated, its only one mark but its really frustrating me. Thanks in advance
    You need to divide by ten thousand; not a hundred thousand.
    Offline

    2
    ReputationRep:
    (Original post by Zarah01)
    are there any ones you wanted in particular? cos we got them on the school VLE, i could download the one you wanted onto here if you want?
    That would be so wonderful if you could! Thanks! I'm looking for June 2008 if that's possible
    Offline

    11
    ReputationRep:
    (Original post by Zarah01)
    are there any ones you wanted in particular? cos we got them on the school VLE, i could download the one you wanted onto here if you want?
    Can you upload all old legacy papers please? I might have time to o them later on.
    Offline

    11
    ReputationRep:
    (Original post by krisshP)
    Can you upload all old legacy papers please? I might have time to o them later on.
    Are you kidding me? You haven't done them yet?! Each one takes around an hour and 45 minutes!

    KIDDDING
    Offline

    9
    ReputationRep:
    (Original post by usycool1)
    You need to divide by ten thousand; not a hundred thousand.
    oh yeah >.< silly mistakes, still dont know how to do the q though
    Offline

    9
    ReputationRep:
    (Original post by hen4r)
    That would be so wonderful if you could! Thanks! I'm looking for June 2008 if that's possible
    2848_2008_Summer_answers.pdf
    Offline

    9
    ReputationRep:
    (Original post by krisshP)
    Can you upload all old legacy papers please? I might have time to o them later on.
    the papers are on the ocr webage:
    http://www.ocr.org.uk/qualifications...ers-h035-h435/
    Offline

    2
    ReputationRep:
    Thank you so much!
    Offline

    0
    ReputationRep:
    (Original post by Zarah01)
    hey guys, really dreading this exam as i gather most of you are -_-
    can someone please help me on a q from the jan 2010 paper?
    here's the question:

    1f. Scientists monitor the composition of the Earth's atmosphere. They have found that the concentration of carbon dioxide in dry, unpolluted tropospheric air has increased from 300ppm to around 380ppm between 1900 and the present day.
    i) Taking the present day value to be 380ppm, calculate the increase in the percentage of carbon dioxide in the air between 1900 and the present day.

    I converted the values into percentages so,
    380/100000=0.0038% and 300/100000=0.0030%
    so the difference between these values is 0.008, therefore 0.008/0.003

    but according to the mark scheme its meant to be 0.008/8*10^ -3.
    Any help would be appreciated, its only one mark but its really frustrating me. Thanks in advance
    You don't need to divide by 0.003 because they are in percentage, so the answer is just the difference between the two percentages.


    Posted from TSR Mobile
    Offline

    11
    ReputationRep:
    In Jan 2013 q4ci and q4d I don't understand how you get the marks scheme answers. Can somebody please explain?

    Thanks
    Offline

    11
    ReputationRep:
    (Original post by krisshP)
    In Jan 2013 q4ci and q4d I don't understand how you get the marks scheme answers. Can somebody please explain?

    Thanks
    is the answer for 4d thujone?
    Offline

    11
    ReputationRep:
    (Original post by nukethemaly)
    is the answer for 4d thujone?
    Yeah, but how did you know?
    Offline

    11
    ReputationRep:
    (Original post by krisshP)
    Yeah, but how did you know?
    because it's not an alkene haha
    Offline

    11
    ReputationRep:
    (Original post by nukethemaly)
    because it's not an alkene haha
    Q4ci?
 
 
 
Turn on thread page Beta
Updated: March 29, 2014
Poll
Do you like carrot cake?

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.