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    (Original post by thymolphthalein)
    Aha, it's alright.

    Attachment 414837
    Thank you very much !
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    Anyone got any tips what to cover for the AQA AS exam tomorrow?
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    What parts of the green chemistry do we have to know?
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    I domt understand how to work out infrared spectroscopy struggling to answer long exam questions on it
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    (Original post by Kitty201322)
    I domt understand how to work out infrared spectroscopy struggling to answer long exam questions on it
    Top tip is to label the spectra (which is credited by examiner) and identify functional groups. It may ask you to calculate an impirical / molecular formula first to help you.

    For example if there are 2 Os in the molecular formula it can't be a ketone/aldehyde, etc.
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    Does anyone know how to answer this question:
    Antimony is a solid element that is used in industry. The method used for theextraction of antimony depends on the grade of the ore.
    3 (a) Antimony can be extracted by reacting scrap iron with low-grade ores that containantimony sulfide (Sb2S3).
    3 (a) (i) Write an equation for the reaction of iron with antimony sulfide to form antimony andiron(II) sulfide.

    I might be missing something really obvious but I don't get how you're supposed to know how many irons react with the sulfur.
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    (Original post by bob smith 23)
    Does anyone know how to answer this question:
    Antimony is a solid element that is used in industry. The method used for theextraction of antimony depends on the grade of the ore.
    3 (a) Antimony can be extracted by reacting scrap iron with low-grade ores that containantimony sulfide (Sb2S3).
    3 (a) (i) Write an equation for the reaction of iron with antimony sulfide to form antimony andiron(II) sulfide.

    I might be missing something really obvious but I don't get how you're supposed to know how many irons react with the sulfur.
    Is this even F322?> :dontknow:
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    Can someone please explain to me how I do this, and what topic this is. I understand Oxidising alcohols however this question just came up and Im at a lost. Any help is greatly appreciated.

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    (Original post by LordBanter)
    Can someone please explain to me how I do this, and what topic this is. I understand Oxidising alcohols however this question just came up and Im at a lost. Any help is greatly appreciated.


    First things first identify what type of alcohol is it? As the OH is bonded to a C which is bonded to one H (and 2 Cs), it is secondary.

    So, for the top left, the acidified potassium dichromate tells you it is oxidised. Secondary alcohols oxidise (heat under reflux) to form ketones - always.
    So, I think you take off the OH and replace it with a double bond to O.



    Top right: esterification - H comes off the alcohol and OH comes off the carboxylic acid


    Bottom left: Dehydration to form alkenes (isomers) - double bond on different carbons for the two boxes.


    Check the mark scheme and I hope this helps
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    (Original post by itsConnor_)
    First things first identify what type of alcohol is it? As the OH is bonded to a C which is bonded to one H (and 2 Cs), it is secondary.

    So, for the top left, the acidified potassium dichromate tells you it is oxidised. Secondary alcohols oxidise (heat under reflux) to form ketones - always.
    So, I think you take off the OH and replace it with a double bond to O.



    Top right: esterification - H comes off the alcohol and OH comes off the carboxylic acid


    Bottom left: Dehydration to form alkenes (isomers) - double bond on different carbons for the two boxes.


    Check the mark scheme and I hope this helps
    I have the mark scheme I was just looking for a greater understanding, thank you for the help!
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    can someone explain the key point that you need to know for the extraction of metals, alcohols, equlibria and kinetics..
    cheers
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    Name:  Screen Shot 2015-06-01 at 21.22.43.png
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    Hey can someone explain to me why this molecule wouldn't have hydrogen bonds as an intermolecular force? Thanks
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    (Original post by xMillnsy)
    Can someone help me with this question (jan 13, question 4)
    Attachment 415151
    So it tells you that you have 1000dm^3 of H2 - hence you can calculate the moles: 1000/24 = 41.67

    If 49 kJ is released when 3 moles of H2 react, then when 41.67 moles react you divide 41.67 by 3 and then multiply by 49 to get 680..

    I hope this makes sense, it is a bit confusing but the key point is to look at the molar quantities / ratio
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    http://www.thestudentroom.co.uk/g/st...ry_study_group


    join :elefant:
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    (Original post by gabby07)
    Name:  Screen Shot 2015-06-01 at 21.22.43.png
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    Hey can someone explain to me why this molecule wouldn't have hydrogen bonds as an intermolecular force? Thanks

    Since C-H bond is non polar, the H isn't delta positive which is a requirement of hydrogen bonding. For example, in ethanol, there's an OH group. The O is very electronegative causing the Hydrogen to become delta positive so ethanol can form hydrogen bonds. This has Fluorine, a very electronegative element, but hydrogen isn't attached to it
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    (Original post by Year11guy)
    Since C-H bond is non polar, the H isn't delta positive which is a requirement of hydrogen bonding. For example, in ethanol, there's an OH group. The O is very electronegative causing the Hydrogen to become delta positive so ethanol can form hydrogen bonds. This has Fluorine, a very electronegative element, but hydrogen isn't attached to it
    Thanks
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    (Original post by gabby07)
    Name:  Screen Shot 2015-06-01 at 21.22.43.png
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    Hey can someone explain to me why this molecule wouldn't have hydrogen bonds as an intermolecular force? Thanks
    Hydrogen has to be attached to a very electronegative atom (generally oxygen/nitrogen/fluorine). C-H bonds are not very polar compared to an O-H/H-F/N-H bond.
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    (Original post by itsConnor_)
    Not on the spec. We only need to know specifics about catalytic converters

    Accepted you
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    The last question 8b I got everything except the part when we have to find the molecular formula of G ! How did they get C4H6O2??? I am so confused I found the mole ratio 2:3:1 which is right

    Plz someone help me

    Thank you so much
    Attached Images
  1. File Type: pdf F322_Jun14.pdf (498.9 KB, 43 views)
  2. File Type: pdf F322_Jun14_MS.pdf (569.2 KB, 38 views)
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    (Original post by yoomi)
    The last question 8b I got everything except the part when we have to find the molecular formula of G ! How did they get C4H6O2??? I am so confused I found the mole ratio 2:3:1 which is right

    Plz someone help me

    Thank you so much
    Molecular ion peak (M+) is at 86 = molar mass = 2 times the molar mass of the impirical formula, so double everything
 
 
 
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