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    (Original post by ozzie2)
    Uhm what are you talking about, wot pic. Also what happened to those kik group chats? I miss them and u bullying me :cry:
    Hah they died.

    Wut you don't remember the famous dina photoshop of you? :sad:

    I COULD ALWAYS POST AND SHOW YOU? :awesome:
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    (Original post by EmilyPBonner)
    It should always mention it in the question, if there is an enthalpy change next to the reaction you can assume that is for the forward reaction.
    Is it awkward having a surname as Boner?
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    (Original post by Gladiatorsword)
    Ok. Say you're given a reaction with an negative enthalpy change - its exothermic. But how do you know if the forward reaction is exothermic or the backwards? ??

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    As said above it will always be said or shown. For example, it may show deltah=-45. Because it's - sign, we know it's an exothermic reaction.
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    (Original post by Dinaa)
    Hah they died.

    Wut you don't remember the famous dina photoshop of you? :sad:

    I COULD ALWAYS POST AND SHOW YOU? :awesome:
    Just like me in 3 weeks, and oh I might remember lol but that don't even look like me now,
    Pls don't post it I will cri and be sad
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    (Original post by Gladiatorsword)
    Ok. Say you're given a reaction with an negative enthalpy change - its exothermic. But how do you know if the forward reaction is exothermic or the backwards? ??

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    It will always be the forwards reaction when given in an exam question, or otherwise it will specify. Don't forget that the ΔH in endothermic reactions is POSITIVE and the ΔH in exothermic reactions is NEGATIVE.
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    (Original post by ozzie2)
    Just like me in 3 weeks, and oh I might remember lol but that don't even look like me now,
    Pls don't post it I will cri and be sad
    What does ozzie look like now then? :rolleyes:
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    (Original post by ozzie2)
    Incoming 300 private messages from people asking for answers. But I'm sure you did fine and if you didn't do as well as you hoped, it is only worth 20% as far as I know and if you do well in the exams you should still be able to get a good grade
    lol yep i got loads. yeah i heard somewhere you can get a very low mark and still get an A
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    Chemistry aqa empa help/ tips anyone?
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    (Original post by Dinaa)
    What does ozzie look like now then? :rolleyes:
    I am beautiful swan now

    (Original post by thatgr)
    lol yep i got loads. yeah i heard somewhere you can get a very low mark and still get an A
    Yeah it is pretty possible, the big one is unit 2 paper which is worth almost 50% so make sure you do well in that and you should be ok
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    (Original post by ozzie2)
    I am beautiful swan now



    Yeah it is pretty possible, the big one is unit 2 paper which is worth almost 50% so make sure you do well in that and you should be ok
    i lold

    pics or gtfo
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    (Original post by frozo123)
    Is it awkward having a surname as Boner?
    No but it is annoying when I encounter immature people like you
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    (Original post by Dinaa)
    i lold

    pics or gtfo
    I still gat my insecurities kid soz

    (Original post by frozo123)
    go sort your boner out
    The banter is unreal, I am so jealous
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    (Original post by ozzie2)
    I still gat my insecurities kid soz



    The banter is unreal, I am so jealous
    I gave you some rep so you don't feel too insecure.
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    I've had a fair number of reports complaining about people trying to cheat on their ISA/EMPA exams on here. Trying to cheat on your exams is strictly against the rules on TSR and attempting to do so can lead to a ban from the site. More importantly, AQA do seem to be monitoring the site and have said that they are well within their rights to take action against any student who is involved in malpractice like this. I would therefore urge all of you to be careful in what you post. Disclosing information using Private Messages (PMs) is not allowed either.

    If you do see anyone breaking the rules (either on here or if they send you a PM), you can report them to the moderation team using the report function and one of us will try to answer it ASAP.

    And while I'm here - many people also seem to be giving away their emails to request help with their ISA/EMPA tasks. Please be very careful with giving away your email address to strangers on here unless you're sure that they are who they say they are. We have had some instances of TSR users getting abusive or threatening emails from people because of revealing their email addresses (either publicly or by PM) so again, please be careful.

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    Can someone explain the whole primary and secondary alcohols thing to me. Quite a fair bit but it is appreciated.

    Is it primary to aldehyde --> Carboxylic acid
    Secondary to ketone
    Tertiary do not oxidise - ( Can someone explain why)?

    Reagent is sulphuric acid and acidified potassium dichromate is the oxidising agent.

    Need some help with the whole fehlings and tollen's shiz. Sound my homies.
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    (Original post by Super199)
    Can someone explain the whole primary and secondary alcohols thing to me. Quite a fair bit but it is appreciated.

    Is it primary to aldehyde --> Carboxylic acid
    Secondary to ketone
    Tertiary do not oxidise - ( Can someone explain why)?

    Reagent is sulphuric acid and acidified potassium dichromate is the oxidising agent.

    Need some help with the whole fehlings and tollen's shiz. Sound my homies.
    For Tollen's reagent, the solution forms a silver mirror only if an aldehyde is present. If no silver mirror is formed then it is a ketone or something else. Similar with Fehling's, if an aldehyde is present it goes brick red (i think) and no reaction with a ketone

    Yes primary alcohols oxidise to an aldehyde then a carboxylic acid and secondary to a ketone and tertiary do not, I don't think you need to know why tertiary don't oxidise
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    (Original post by Super199)
    Can someone explain the whole primary and secondary alcohols thing to me. Quite a fair bit but it is appreciated.

    Is it primary to aldehyde --> Carboxylic acid
    Secondary to ketone
    Tertiary do not oxidise - ( Can someone explain why)?

    Reagent is sulphuric acid and acidified potassium dichromate is the oxidising agent.

    Need some help with the whole fehlings and tollen's shiz. Sound my homies.
    Tertiary does not oxidise because the carbon with OH does not have an H
    In primary and secondary the carbon with OH have H on it which is removed to allow the formation of double bond with O.

    Reagent is dilute sulphuric acid and potassium/sodium dichromate (VI). You have to put oxidation state. You don't have to say acidified because by mentioning sulfuric acid it's already acidic.

    Fehling and
    Tollen's detect aldehyde
    From quick googling. But I haven't learnt them lol

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    (Original post by C0balt)
    Tertiary does not oxidise because the carbon with OH does not have an H
    In primary and secondary the carbon with OH have H on it which is removed to allow the formation of double bond with O.

    Reagent is dilute sulphuric acid and potassium/sodium dichromate (VI). You have to put oxidation state. You don't have to say acidified because by mentioning sulfuric acid it's already acidic.

    Fehling and
    Tollen's detect aldehyde
    From quick googling. But I haven't learnt them lol

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    I don't get the tertiary alcohol bit. The carbon with OH does not have an H?

    What is the stuff about the chromium stuff orange to green or the other way round can't remember? Something about reduction???

    Sound
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    (Original post by Super199)
    I don't get the tertiary alcohol bit. The carbon with OH does not have an H?

    What is the stuff about the chromium stuff orange to green or the other way round can't remember? Something about reduction???

    Sound
    The carbon which has hydroxyl group attached to it has three carbon atoms so there is no H atom on its own attached to the said carbon. Draw a tertiary alcohol and you will see. But I don't think the explanation is on any syllabus.

    The chromium (VI) in dichromate has orange colour and chromium (III) is green. It is reduced in oxidation of alcohol this is where the colour change comes from.

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    (Original post by Super199)
    Can someone explain the whole primary and secondary alcohols thing to me. Quite a fair bit but it is appreciated.

    Is it primary to aldehyde --> Carboxylic acid
    Secondary to ketone
    Tertiary do not oxidise - ( Can someone explain why)?

    Reagent is sulphuric acid and acidified potassium dichromate is the oxidising agent.

    Need some help with the whole fehlings and tollen's shiz. Sound my homies.
    Primary alcohol ->

    The -oh group is attached to a carbon. That carbon can be on it's own (methanol) or attached to another carbon, like ethanol, propanol.

    When oxidised with H2SO4/K2Cr2O7 [O], it becomes an aldehyde. This must be distilled immediately as it is made to prevent further oxidation.

    If left to oxidise further as a reflux in excess H2SO4/K2Cr2O7 2[O], it becomes a carboxylic acid.

    Secondary alcohol is when the -OH group is attached to a carbon and that carbon is attached to two other carbons, like 2-methylpropan-2-ol. When oxidised using H2SO4/K2Cr2O7 it forms a ketone.

    Tertiary alcohol is when the -og group is attached to a carbon, and that carbon is attached to 3 other carbons. Such as 1-dimethyl propan-1-ol. This WON'T oxidise.

    If the K2Cr2O7 has been oxidised, it will go from orange to green, if not it will remain orange hence why tertiary alcohols stay orange as they cannot oxidise at all.

    Hope this helps
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