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

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    (Original post by alfmeister)
    Attachment 546887
    There you go. Just ask if you don't understand anything.
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    Thanks. I appreciate it.

    At the end you doubled the concentration because there were two Na ions present. So if there had been 3, you would have times by 3 right?

    Thanks again
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    (Original post by SGHD26716)
    Thanks. I appreciate it.

    At the end you doubled the concentration because there were two Na ions present. So if there had been 3, you would have times by 3 right?

    Thanks again
    Yes you're exactly right.
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    Predictions for the paper tomorrow?
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    (Original post by h3rmit)
    Here you go
    Legend 👊


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    Based on what didn't come up in Breadth and the fact that Depth is more mathmatical I predict that we will get:

    A percentage yeid/ atom economy
    An ideal gas equation
    Infrared spectroscopy
    Reaction mechanisms
    Structure and bonding questions
    Ionisation energies
    More mol calculations
    Polymers
    Isomers and Steroisomerism
    Periodicity
    Enthalpy with a Hess cycle style
    Boltsman graphs/Catalysts
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    Can someone please explain everything we need to know for ionisation energies.
    I forgot the trends across and down the group. especially drawing the graphs for them
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    (Original post by 4nonymous)
    Can someone please explain everything we need to know for ionisation energies.
    I forgot the trends across and down the group. especially drawing the graphs for them
    Generaly the trend across the group is that the first ionisation energy increases across the group( left to right)
    But beware of the dip between group 2-3 because of the new sheilding of a p orbital means less energy is needed for group 3 elements than group 2.
    Also, beware of the Group 5-6 dip which is caused by electron repulsion in the p orbital that contains 6 electrons.

    Down the group ionisation energy decreases because the atomic radius increases so electrons are less attracted to the nucleus also there is more electron shielding so the outer electrons have less attraction so less energy is needed to remove one.
    For the graphs just look where a massive gap is as it will tell you where the change in electron shell is
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    (Original post by 4nonymous)
    Can someone please explain everything we need to know for ionisation energies.
    I forgot the trends across and down the group. especially drawing the graphs for them
    Across a group, there is a GENERAL INCREASE because the NUCLEAR CHARGE INCREASES, electrons fill the same shell and so the SHIELDING IS SIMILAR. The attraction between outer electrons and nucleus increases and ATOMIC RADIUS DECREASES, thus becoming harder to remove one electron from outer shell.

    There is a general increase but there is a dip for boron due to filling of p orbitals and drop in oxygen due to pairing of p orbitals.


    Down a group the first ionisation energy GENERALLY DECREASES as the nuclear charge increases but electrons are in the same she'll so SHIELDING INCREASES, and because of the increased shielding the attraction between nucleus and outer electron DECREASES and the ATOMIC RADIUS INCREASES and so it becomes easier to remove the outer electron


    I wrote important words in CAPITALS because I don't know how to write in bold lol
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    (Original post by asinghj)
    Across a group, there is a GENERAL INCREASE because the NUCLEAR CHARGE INCREASES, electrons fill the same shell and so the SHIELDING IS SIMILAR. The attraction between outer electrons and nucleus increases and ATOMIC RADIUS DECREASES, thus becoming harder to remove one electron from outer shell.

    There is a general increase but there is a dip for boron due to filling of p orbitals and drop in oxygen due to pairing of p orbitals.


    Down a group the first ionisation energy GENERALLY DECREASES as the nuclear charge increases but electrons are in the same she'll so SHIELDING INCREASES, and because of the increased shielding the attraction between nucleus and outer electron DECREASES and the ATOMIC RADIUS INCREASES and so it becomes easier to remove the outer electron


    I wrote important words in CAPITALS because I don't know how to write in bold lol

    Why are you shouting lol

    Thanks. Really helpful
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    (Original post by JamieHarris1998)
    Generaly the trend across the group is that the first ionisation energy increases across the group( left to right)
    But beware of the dip between group 2-3 because of the new sheilding of a p orbital means less energy is needed for group 3 elements than group 2.
    Also, beware of the Group 5-6 dip which is caused by electron repulsion in the p orbital that contains 6 electrons.

    Down the group ionisation energy decreases because the atomic radius increases so electrons are less attracted to the nucleus also there is more electron shielding so the outer electrons have less attraction so less energy is needed to remove one.
    For the graphs just look where a massive gap is as it will tell you where the change in electron shell is
    Thank you
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    What do you guys think you got in the breadth in chemistry paper?
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    what do you guys think the practical questions will be about?
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    (Original post by 11...)
    What do you guys think you got in the breadth in chemistry paper?
    Hopefully a C or B
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    (Original post by 4nonymous)
    Why are you shouting lol

    Thanks. Really helpful
    Hehe itll helps to stick better in your head
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    I hope we are not going to get questions that hardly ever appeared in past papers. Although the past papers from the old spec are really useful, it is not going to be the same. I wish we were not the first year to do this new spec, due to the lack of past papers. only 2 is available from the new spec like.... but then again, chemistry doesn't change lol
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    When you calculate percentage yield, do you take the coefficient in front of the element into account?
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    do you think they'd scrutinise me spelling carcinogenic wrong?
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    (Original post by ActuallyIDo)
    do you think they'd scrutinise me spelling carcinogenic wrong?
    Probably not, as long as they could actually understand what it's meant to mean
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    Hey guys anyone got specimen paper 1 second set haven't tried it yet would be great if I try it b4 exam even though it's bredth and I should've done it b4 xd
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    (Original post by noname122344728)
    Hey guys anyone got specimen paper 1 second set haven't tried it yet would be great if I try it b4 exam even though it's bredth and I should've done it b4 xd
    Go on the Physics Maths Tutor site and you'll be able to find it under the OCR A Chem Papers from 2015.


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