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    (Original post by TheLifelessRobot)
    What do people think the grade boundaries will be like for an A? I reckon this paper was a bit harder than last years so I'd guess 55 for an A.
    53-55, 53 was for last year.
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    (Original post by Studious_Student)
    53-55, 53 was for last year.
    Last year was 57 for an A.
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    (Original post by TheLifelessRobot)
    Last year was 57 for an A.
    Oh shoot I apologise lol, read it incorrectly -_- I hope it's around 55 none the less, I feel like I did pretty well except for losing around 10-12 marks.
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    Crap I just realised that I didn't draw all the bonds for the isomers question. It asked for the displayed formula
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    For the balancing equation one I put
    Cu2(OH)2CO3 + 2HCl ---> CuCl2 + CuCo3 + 2H2O
    For for observations I put ppt to Blue solution of [Cu(H2O)6]^2+
    >.<
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    (Original post by SirRaza97)
    EDIT: Thanks to everyone who has helped in this thread. If anyone can remember the marks for each question I will add them in for you guys! Also the Bold stuff after some thought are probably the correct answers or something along the lines of it. Good luck to everyone in the rest of their exams

    Here is my unofficial mark scheme. Anything in bold I am not sure if it's right. So if you have any idea then please tell me so i can add it! If i have missed anything out then aslo let me know!

    Section A

    1.
    a) Relative Atomic mass Definition
    b) Magnetic Field
    c) - Ions accept electrons -Current is formed which is proportional to abundance
    d) Something like 28.065 for the RAM
    e) Similarity= Peaks still at original m/z values becuase +1 ions are still formed/
    same relative abundance (or same height of peaks) because same sample is used so similar amount of the isotopes are present
    -Difference - Peaks at half the m/z values becasue high energy electrons will produce +2 ions

    2. (Can't rmember what topic this was. I think it was about Van Der Waals)
    a) -Electron Density randomly shifts -Creating areas of +ve and -ve charge on molecule - Attraction between molecules which is intermolecular force/VDW
    b) O-H bond big electronegative difference allows for hydrogen bonds. Hydrogen bonds are stronger than VDW.
    c) Fractional Distiallation will sperate these
    d) The Se molecule is larger. This means the VDW forces are stronger between molecules

    3. (Questions about Alkanes?)
    a) Group is alkane
    b) 2,2,4 - trimethylpentane (might accept 2,4,4 - trimethylpentane)
    c) C8H18 + 12.5O2 ------> 9H2O + 8CO2
    d) but-1-ene
    e) C14H30
    f) Thermal Cracking. High temp and high pressure
    g) Isomers question. Chain isomer = H2C=C(CH3)2 Postion isomer = But-2-ene Functional Isomer = Cyclic Alkane so cyclicbutane

    4. (The weird reactions and the shapes question?)
    a) Balancing equation I couldn't remember
    b) Cu2(OH)2CO3 + 4HCl -----> 2CuCl2 + 3H2O + CO2
    c) Effervescense
    d) Cu3O8H2C2 or in the structural form
    e) Shapes question - SF6 = Octohedral , 90 degrees -SF4 = See-Saw shape. Lone pair on the horizontal plane. Angles 90, 120 or 180 degrees. Probably will accept -2.5 degrees off each angle.

    Section B

    5. (Period 3 stuff)
    a) - Ionisation energies increase -Increasing proton number - Similar Shielding -Attraction between outer electron and nuclues gets stronger -The bigger nuclear charge reduces atomic radius (I don't think this point is needed)
    b) -Silicon has highest melting point. -Because of macromolecular/Giant covelant structure. -Strong covelant bonds throughout structure. -Requires high amounts of energy to break.
    c) The elements that you could say were Aluminuim because removing electron from 3p shell and Sulphur because of pair repulsion.
    d) -Element Y is Sulphur. -Large jump in eneries from 6th to 7th ionisation enegies -So 7th electron in inner shell so sulphur must be the element Y.

    6. (Calculations)
    a) 0.113m3 (3 sig figs needed)
    b) 1065 Kg or 1.065x106 g
    c) Percentage yield = 49.3%
    d) Method 1 because its 100% atom economy. Only producing one product.
    Do u think saying heat under reflux instead of fractional distillation would get u marks since it was two different compounds that were not alkanes with relatively low boiling points.
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    (Original post by 97Y)
    Electric field accelerates, hence the reference to velocity, the magnetic field deflects. I'm afraid that you're wrong
    I was stating that magnetic field was correct and that she had confused this question with the electric field and acceleration from another question.
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    (Original post by Haidar.stan)
    Do u think saying heat under reflux instead of fractional distillation would get u marks since it was two different compounds that were not alkanes with relatively low boiling points.
    I am not so sure. That does sound like a suitable way of doing it.
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    I wrote 'Thermalytic' instead of 'Thermal' for the cracking question, would that be accepted? Also, for the last Atom economy question I just put that 'Method 1 because only one product is produced' - I didn't write about it being 100%, would I still get the mark or? Thanks.
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    (Original post by SirRaza97)
    I am not so sure. That does sound like a suitable way of doing it.
    I put fractional distillation then crossed it out since the other compound had sulfur in it. Ahh i hope they allow reflux cuz its perfectly reasonable.
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    (Original post by Haidar.stan)
    Do u think saying heat under reflux instead of fractional distillation would get u marks since it was two different compounds that were not alkanes with relatively low boiling points.
    I thought that!!!! They weren't hydrocarbons so I just said distillation, instead of fractional distillation. I should have put reflux too omg, that's what I meant :l
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    (Original post by thedoctor12)
    I wrote 'Thermalytic' instead of 'Thermal' for the cracking question, would that be accepted? Also, for the last Atom economy question I just put that 'Method 1 because only one product is produced' - I didn't write about it being 100%, would I still get the mark or? Thanks.
    I've never heard of the word thermalytic before. What does it mean? If it's the same as thermal cracking then yeah I guess. It sounds like you just put the word thermal and catalytic cracking together
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    (Original post by SirRaza97)
    Well in method 1 both equations lead to only 1 product so I don't know how that is not 100% atom economy. What poducts are lost? They all go to make 1 product. That's 100%.
    I thought that the first step had 2 products, of which the P4O10 was the minor product?
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    Posted from TSR Mobile

    What u guys think the grade boundaries be??
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    (Original post by Yayvillee)
    I thought that the first step had 2 products, of which the P4O10 was the minor product?
    The first step equation was

    P4 + 5O2 ----> P4O10

    Also the question said we didnt need to do a calculation. That is a kind of hint to tell us it should be obvious which has a better atom economy. Plus it was 1 mark.
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    (Original post by emmaharvard)
    posted from tsr mobile

    what u guys think the grade boundaries be??
    a - 68
    b - 63
    c - 57
    d - 70
    e - 54
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    (Original post by SirRaza97)
    a - 68
    b - 63
    c - 57
    d - 70
    e - 54
    You chat ****
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    (Original post by alevelsarepoo)
    You chat ****
    Nah man I'm sitting on that D boi
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    (Original post by Haidar.stan)
    Do u think saying heat under reflux instead of fractional distillation would get u marks since it was two different compounds that were not alkanes with relatively low boiling points.
    I also didn't wanna write fractional distillation because of this! I can't remember the exact wording but
    I wrote something like heat the mixture to 6 degrees (lol) because that was the boiling point of one of them so this would like evaporate off? Lmfao
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    (Original post by thedoctor12)
    I thought that!!!! They weren't hydrocarbons so I just said distillation, instead of fractional distillation. I should have put reflux too omg, that's what I meant :l
    Exactly, they should allow both tbh, although fractional distillation doesnt make sense in this question. The chem1 spec does mention reflux in its content.
 
 
 
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