Hey there! Sign in to join this conversationNew here? Join for free
    Offline

    0
    ReputationRep:
    Do you think they will accept 2,2,4 methylpentane instead of 2,2,4 trimethylpentane


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by vinchy)
    Cracking question,i just put high temperature is that enough?
    Hello there,
    I think the questions asked for 2 conditions :/, but did you put thermal cracking though?
    I've put high temp (700 degrees)
    High pressure ( >1000kPa)
    Offline

    0
    ReputationRep:
    Section A

    1.
    a) Relative Atomic mass Definition (2 marks)
    b) Magnetic Field (1 mark)
    c) - Ions accept electrons -Current is formed which is proportional to abundance (2 marks)
    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 (4 marks)

    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 (3 marks)
    b) O-H bond big electronegative difference allows for hydrogen bonds. Hydrogen bonds are stronger than VDW.
    c) Fractional Distiallation will sperate these (1 mark)
    d) The Se molecule is larger. This means the VDW forces are stronger between molecules (2 marks)

    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 cyclic butane (3 marks)

    4. (The weird reactions and the shapes question?)
    a) Balancing equation I couldn't remember (1 mark)
    b) Cu2(OH)2CO3 + 4HCl -----> 2CuCl2 + 3H2O + CO2 (2 marks)
    c) Effervescense (1 mark)
    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. (6 marks)

    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) (4 marks)
    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. (2 marks)

    6. (Calculations)
    a) 0.113m3 (3 sig figs needed)
    b) 1065 Kg or 1.065x106 g (3 marks)
    c) Percentage yield = 49.3%
    d) Method 1 because its 100% atom economy. Only producing one product. (1 mark) [/QUOTE]

    I only wrote in the marks for the ones I was sure on, we can add to this if anyone remembers anymore
    Offline

    3
    ReputationRep:
    (Original post by Pluto98)
    Hello there,
    I think the questions asked for 2 conditions :/, but did you put thermal cracking though?
    I've put high temp (700 degrees)
    High pressure ( >1000kPa)
    Oh **** i didnt really read the question.
    Offline

    0
    ReputationRep:
    (Original post by EmmaHarvard)
    The shape one was the total marks and the scoring points??
    It was 6 marks for the whole table, probably 3 marks for shape 1 (SF6) and 3 marks for shape 2 (SF4) eventho u didn't have to name shape 2 but it was quite a complex shape and bonding angle was hard to figure out.
    Offline

    3
    ReputationRep:
    (Original post by Pluto98)
    Hello there,
    I think the questions asked for 2 conditions :/, but did you put thermal cracking though?
    I've put high temp (700 degrees)
    High pressure ( >1000kPa)
    i put thermal cracking and condition high temp
    Offline

    1
    ReputationRep:
    (Original post by SirRaza97)
    If anyone remembers I will add them
    Thanks 🙂
    Offline

    0
    ReputationRep:
    (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.
    I got something different for 4d ( Cu2(OH)CO3 ) i thought you had to put it in that form :?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by fasdaman2212)
    I got something different for 4d ( Cu2(OH)CO3 ) i thought you had to put it in that form :?
    I dont think it matters
    Offline

    3
    ReputationRep:
    (Original post by jaymistry233)
    The answer in the 2010 past paper refered to the changing of velocity of the cations by altering the strength of the electric field generated by the negatively charged accelerating plates so that a spectrum of ions of different m/z ratios could be collected. The question asked how a full spectrum could be observed, changing the electric field strength was one of many factors.
    Electric field accelerates, hence the reference to velocity, the magnetic field deflects. I'm afraid that you're wrong
    Offline

    1
    ReputationRep:
    Thanks for making this btw,
    does anyone remember the actual wording of the question 5c? You mentioned two answers, aluminium and sulphur and i only wrote sulphur, bc paired orbital, thinking i read it wrong..

    Also for the successive ionisation energies i think i wrote oxygen instead of sulphur bc again i'm an idiot that doesn't read questions properly, i explained it and stuff, do you reckon i'll get partial marks? Or none cause they asked for period 3 properties? Thanks
    Offline

    0
    ReputationRep:
    (Original post by hp707)
    Thanks for making this btw,
    does anyone remember the actual wording of the question 5c? You mentioned two answers, aluminium and sulphur and i only wrote sulphur, bc paired orbital, thinking i read it wrong..

    Also for the successive ionisation energies i think i wrote oxygen instead of sulphur bc again i'm an idiot that doesn't read questions properly, i explained it and stuff, do you reckon i'll get partial marks? Or none cause they asked for period 3 properties? Thanks
    It was something in the lines of
    Name one element in period 3 which deviates from.this general trend
    If you get the element wrong.. It is still possible to get marks..as sometimes the explanation may be independant of the initial answer
    Offline

    1
    ReputationRep:
    (Original post by fasdaman2212)
    It was something in the lines of
    Name one element in period 3 which deviates from.this general trend
    If you get the element wrong.. It is still possible to get marks..as sometimes the explanation may be independant of the initial answer
    Thanks! So in terms of 5c will i get the mark as I did mention one? (Sulphur) The wording of this unofficial markscheme made me think i shouldve mentioned two?..
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by hp707)
    Thanks! So in terms of 5c will i get the mark as I did mention one? (Sulphur) The wording of this unofficial markscheme made me think i shouldve mentioned two?..
    No you only had to mention one but there are 2 possiblities
    Offline

    1
    ReputationRep:
    (Original post by SirRaza97)
    No you only had to mention one but there are 2 possiblities
    sick, thanks!
    Offline

    12
    ReputationRep:
    (Original post by Bloom77)
    Omg same!!


    Posted from TSR Mobile
    Nice to know I'm not alone.

    (Original post by SirRaza97)
    Haha good chem5 application. That would be pretty hard for an AS sudent xD
    Yeah, but they asked for cucl2 not cucl4 This is like the stupid mg2n3 vs mgn6 question all over again lol.
    Offline

    10
    ReputationRep:
    How the hell did I get the volume at 0.451m3, ffs
    Wish someone had the paper so i could see
    Offline

    0
    ReputationRep:
    (Original post by Dankailen)
    how many marks do i lose? i did the correct calculations
    You must have divided by the combined masses of all isotopes to obtain the answer of 32. You must divide them by the total abundance, which in the case was 100. You will most likely lose 1 or 2 marks.
    Offline

    2
    ReputationRep:
    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.
    Offline

    9
    ReputationRep:
    (Original post by Danny786)
    How the hell did I get the volume at 0.451m3, ffs
    Wish someone had the paper so i could see
    I got the same answer as you, we basically forgot to multiply the moles of Phosphorous by 4 as the molecule was P4, we will probably get 2-3/4 marks if you got everything else right, as the method marks carry over.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Have you ever participated in a Secret Santa?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.