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A level chemistry paper 1 unofficial markscheme 2018 watch

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    Born Haber labelling (3 marks)
    Lattice formation: -3888 (3 marks)
    3x10 Kpa-2
    Entropy: 181
    Gibbs free: -1063
    Abundance: 80% (3 marks)
    TOM distance: 1.54 (5 marks
    Ph: 13.10 & 4.28
    Electrode potential: +0.18 (1 marks)
    Ideal gas volume: 133cm (4 marks)
    Concentration: 0.0218
    Isomerism: E-Z
    Bond angle: 104.5

    Aluminium question

    AlCl3 + 6 H2O --> Al(H2O)6]3+ + 3 Cl-
    2[Al(H2O)6]3+ + 3 CO32- —> 2 Al(H2O)3(OH)3 + 3 CO2 + 3 H2O
    Observations: white precipitate & effervescence
    [Al(H2O)6]3+ + 3 OH- --> Al(H2O)3(OH)3 + 3 H2O
    Observation: white precipitate
    Al(H2O)3(OH)3 + 3 OH- -->; [Al(OH)6]3- + 3 H2O
    Observations: colourless solution

    Back titration (7 marks)
    X=1

    Bonding (6mark)
    NaBr
    giant ionic structure
    Strong Ionic bond(electrostatic force) between ions
    So high melting point
    Na
    Giand metallic structure
    Metallic bonding between delocalized electrons and Na+ ions
    But weaker than ionic bond between Na+ and Br-
    So lower melting point
    NaI
    Giant ionic structure
    But I- larger so lower charge density
    More sheilding
    So ionic bong between Na+ and I- is weaker
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    It is not optical isomerism.
    [V(H2O)4Cl2)]+ is E-Z isomerism
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    80% abundance of ion
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    For 6 marks question:
    NaBr
    giant ionic structure
    Strong Ionic bond(electrostatic force) between ions
    So high melting point
    Na
    Giand metallic structure
    Metallic bonding between delocalized electrons and Na+ ions
    But weaker than ionic bond between Na+ and Br-
    So lower melting point

    NaI
    Giant ionic structure
    But I- larger so lower charge density
    More sheilding
    So ionic bong between Na+ and I- is weaker
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    (Original post by Admixtus)
    It is not optical isomerism.
    [V(H2O)4Cl2)]+ is E-Z isomerism
    Okay thank you. Will change
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    (Original post by alevelstruggless)
    80% abundance of ion
    Thank you
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    (Original post by 67823)
    Lattice formation: -3888
    3x10 Kpa-2
    Entropy: 181
    Gibbs free: -1063
    Abundance: 80%
    TOM distance: 1.54
    Ph: 13.10 & 4.28
    Electrode potential: +0.18
    Ideal gas volume: 133cm
    Concentration: 0.0218
    Isomerism: E-Z
    Bond angle: 104.5

    Aluminium question

    AlCl3 + 6 H2O --> [Al(H2O)6]3+ + 3 Cl-
    2[Al(H2O)6]3+ + 3 CO32- --> 2 Al(H2O)3(OH)3 + 3 CO2 + 3 H2O
    Observations: white precipitate & effervescence
    [Al(H2O)6]3+ + 3 OH- --> Al(H2O)3(OH)3 + 3 H2O
    Observation: white precipitate
    Al(H2O)3(OH)3 + 3 OH- --> [Al(OH)6]3- + 3 H2O
    Observations: colourless solution

    Back titration (7 marks)
    X=1

    Bonding (6mark)
    NaBr
    giant ionic structure
    Strong Ionic bond(electrostatic force) between ions
    So high melting point
    Na
    Giand metallic structure
    Metallic bonding between delocalized electrons and Na+ ions
    But weaker than ionic bond between Na+ and Br-
    So lower melting point
    NaI
    Giant ionic structure
    But I- larger so lower charge density
    More sheilding
    So ionic bong between Na+ and I- is weaker
    Please add to this thread
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    I got 85
    (88*85)+(87*7.5)+(86*7.5)/1000 = 87.7
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    which exam board?
 
 
 

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