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    (Original post by Ferdous Shah)
    Where is it released? And how long does it normally take for an unofficial mark scheme to come out?
    Never usually one for salters since hardly anyone does it
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    I thought the coating would be a non conductor since we were talking about electricity

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    For the isomers did you get 2? I got 2 and named one E and the other Z ?

    Cold drawing: The chains are pulled making them straight and more crystalline so chains are closer together and so stronger IMF so mor energy needed to break them etc...
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    (Original post by Zuzuvela)
    It requires 2 moles of bromine

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    Did it explicitly say 2 moles?
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    1.

    Secondary structure– folding of the amino acid chain (alpha helix and beta pleated sheets) Tertiary structure – further folding of the secondarystructure

    Describe activesite and it's function – specific shape, where the substrate binds

    Partial hydrolysisof trypsin – broke the right handside amide bond only

    Benefits of trypsin> bromate (v) catalyst – cheaper?Not toxic?

    5 marker on ESC,EP, rate orders and substrates stuff – first order then zero order, E + Sreaction is rate determining step at beginning, then enzymes become saturatedso the EP to E + P becomes the rate determining step

    Rate of reaction at70 degrees – hydrogen bonds broken, enzyme denatures, active site changes shape

    2.

    Electrodes / tank,which solution? – Fe was +ve(tank 1?)

    Coating steel? – e.g. paint, to prevent the water andoxygen causing rusting, to prevent the contents reacting with the steel

    Why was there amembrane – allow the flow of electrons

    Iron forming redbrown precipitate - Fe2+ and OH-and Fe3+ and OH- reacted in precipitation reactions to form Fe(OH)2 (greenprecipitate) and Fe(OH)3 (orange precipitate) and that these were then oxidised(from oxygen in the air) to form Fe2O3.xH2O which is a red-brown precipitate

    3.

    Bromine number – 390

    Prove excess– calculated how many moles of KBrO3- would react with the Br- present and saidhow that value is less than the actual number of moles of KBrO3- present

    Bromine number [5] – 7

    Why was there E/Zisomerism? – restricted rotation around double bond, two different groupson each carbon in double bond

    Draw isomers– ZZ, EZ, EE

    Transition metalheterogeneous catalysis – reactants are adsorbed onto the surface, the metaluses the 3d and 4s electrons to form weak bonds to the reactants, bonds in thereactants weaken and break, bonds in products form, products diffuse away fromthe surface

    Following BrO3-reaction – colorimetry, Br2 iscoloured, rest colourless, colour changes as reaction progresses

    Rate equation – 1st order, 1storder, 2nd order

    Temperatureaffecting reaction rate? – would loss of the reactants cause rate ofreaction to decrease as the concentrations of the reactants are now lower

    4.

    Draw polyester -

    What condensationpolymer is this? – polyester

    Why did Carothersgo ahead with polyamides? – polyesters do id-id and pd-pd, polyamidesform hydrogen bonds too, hydrogen bonds stronger than others, more energyneeded to separate chains so polyamides are strongerCold-Drawing – stretching thefibre to form a neck which is highly crystallised, chains are closer togetherso intermolecular bonds are stronger

    5.

    Functional groups present - aldehyde, ether, phenol

    Oxidising aldehyde to carboxylic acid – acidifiedpotassium dichromate

    IR spectrum – apocylsin

    Mass spectrum -

    Recrystallisation –dissolve in minimum amount of hot water, cool to allow to recrystallize, vacuumfiltrate to remove soluble impurities, wash with cold water and dry in adesiccator

    Nucleophillicaddition -I've added what I remember, feel free to change if it's wrong.
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    (Original post by LewisEdwards1234)
    I go 195g, not sure where people got the 390g from as the mass of the c6h10 was 82 then bromine is 79.9x2 so you do (79.9x2)/ 82 then multiply that by 100
    You did the whole thing correct, the only problem you've come across is that the molecule bromine reacted with was hexa-1,6-diene (the -1,6- may have been different) so what that means is 2 bromine molecules react with 1 molecule of hexadiene as there are two double bonds. So you would simply do 195x2 = 390. You will most likely only drop one mark so don't worry.
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    (Original post by Amyfrancis97)
    Is it just me that found this paper ridiculously hard? So frustrating. Anyone else not answer the calculation either?
    You are not alone I didn't answer them
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    (Original post by IBerrr)
    - at higher temperatures increased value of rate constant/K, so the rate of reaction will change/increase
    - as volatiles are lost, concentration of reaction changes/decreases
    - change in concentration of reactants will change the rate of reaction

    That's what I put anyway, where i just wrote 'change/decrease' I'm pretty sure in the exam I just put 'change'
    I said this but is that right though, as the answer seems to impy it can both increase or decrease
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    For the for the functional group I put ether, aldehdye and phenol
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    why was it s second order for H+ for the rate equation one?
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    (Original post by LewisEdwards1234)
    I go 195g, not sure where people got the 390g from as the mass of the c6h10 was 82 then bromine is 79.9x2 so you do (79.9x2)/ 82 then multiply that by 100
    There were 2 double bonds so 2 bromine molecules were needed. I got 390 but I doubt it's right bc all my answers were dodgy haha
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    (Original post by LewisEdwards1234)
    I go 195g, not sure where people got the 390g from as the mass of the c6h10 was 82 then bromine is 79.9x2 so you do (79.9x2)/ 82 then multiply that by 100
    The alkene was a diene so you needed two moles of Br2 to get the moles of Br hence being 390g
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    (Original post by KINGYusuf)
    Anyone get 195g for the first Bromine Q?

    Also who else ran out of time
    I ran out of time so bad
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    There's a reason no one does salters, especially salters B due to the fact they manage to make absolute ******** papers. Joke of a course tbh how they've managed to make this paper 5x worse than 2015 is beyond me. No wonder everyone does AQA and this course won't exist next year. JOKE
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    (Original post by Kira Yagami)
    For the for the functional group I put ether, aldehdye and phenol
    That is correct but It said put 2 not 3
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    (Original post by jack.lp.thompson)
    That is correct but It said put 2 not 3
    Could of sworn it said put all
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    (Original post by _MAT_)
    Ahahah if you want to stop dwelling I suggest stop watching this thread
    lol true, but whatever happens happens, really wanted to think I got those 4 marks (theres still the chance I didn't though)

    (Original post by jack.lp.thompson)
    That is correct but It said put 2 not 3
    I'm sure it didn't specify the number it just asked to put the functional groups present other than benzene
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    (Original post by jack.lp.thompson)
    That is correct but It said put 2 not 3
    It said put all, apart from benzene. And there was 3

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    (Original post by IBerrr)
    You did the whole thing correct, the only problem you've come across is that the molecule bromine reacted with was hexa-1,6-diene (the -1,6- may have been different) so what that means is 2 bromine molecules react with 1 molecule of hexadiene as there are two double bonds. So you would simply do 195x2 = 390. You will most likely only drop one mark so don't worry.
    I dont understand how the bromine number can be 390 or 195 when its meant to be how many grams of bromine in 100 grams of sample, surely it has to be less than 100 grams because its impossible to have 195 g of bromine in 100 g of sample?
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    (Original post by Akalanka25)
    I said this but is that right though, as the answer seems to impy it can both increase or decrease
    Well think about it. If a reactant is removed, this will increase the concentration of the one reactant but also decrease the concentration of the other. If the reactant that increases in concentration was second order then the rate will also increase, however, if the reactant REMOVED was second order, then the rate of reaction will decrease. As we were not told which of the reactants were removed, the mark scheme will most likely require candidates to write 'change' as opposed to 'increase/decrease', although I imagine it will ALLOW 'increase/decrease'
 
 
 
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