Join TSR now and get all your revision questions answeredSign up now

AQA GCSE - Unit 3 (P3,B3,C3) New specification papers. Watch

    Offline

    1
    ReputationRep:
    (Original post by Blake-inator)
    new food sources like Mycoprotein (efficient and can the Fusarium can feed on waste materials)
    I know that this is in the revision guide, but when it came up on my mock paper, my teacher said that apparently the mark scheme it doesn't even mention it, so she marked it as wrong :confused:
    Offline

    0
    ReputationRep:
    (Original post by Chlorophile)
    The information about the source has to be comprehensive, so if you were to make up for instance a book, you'd want to name a made up author, page number, etc. To be perfectly honest, it's not really worth the effort to make up a source but there's nothing in principle to stop you doing it. I didn't make up my sources but I specifically chose ones that I could talk about. One of my sources was a 1979 Britannica, the obvious comment being that although it goes into a lot of depth, it is potentially out of date and over complicated for my needs.
    Yep me to, I picked out sources which were incredibly BAD and GOOD. So that I had a lot to talk about
    Offline

    9
    ReputationRep:
    (Original post by Obliviate)
    I know that this is in the revision guide, but when it came up on my mock paper, my teacher said that apparently the mark scheme it doesn't even mention it, so she marked it as wrong :confused:
    really?:eek: my teacher went over this one a lot to make sure we knew it.... is it still worth mentioning do you think or not? if that same question came up
    Offline

    1
    ReputationRep:
    (Original post by Blake-inator)
    really?:eek: my teacher went over this one a lot to make sure we knew it.... is it still worth mentioning do you think or not? if that same question came up
    I personally do think it is worth mentioning, as it is in the revision guide, so I'll probably remember it in that way and it doesn't say on the mark scheme something like "ignore references to using different sources of food".
    But instead of the point about different sources of food, she said that intensive farming should be broke up into two separate points?
    Offline

    3
    ReputationRep:
    Kill3r yep, your method is fine with the alcohols and fuels (i done this as well)
    Offline

    3
    ReputationRep:
    How is an ester made?
    Offline

    1
    ReputationRep:
    (Original post by Captain Anonymous)
    How is an ester made?
    By reacting an alcohol with carboxylic acid, in the presence of an acid catalyst.

    Q: What colours would you get for these positive ions in a flame test?:
    • Lithium
    • Sodium
    • Potassium
    • Calcium
    • Barium
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    How is an ester made?
    This is done by adding the alcohol in the presence of an acid catalyst (I think conc Sulfuric)
    Offline

    0
    ReputationRep:
    (Original post by Obliviate)
    By reacting an alcohol with a carboxylic acid, with a presence of an acid catalyst.

    Q: What colours would you get for these positive ions in a flame test?:
    • Lithium
    • Sodium
    • Potassium
    • Calcium
    • Barium
    Crimson,
    Yellow,
    lilac,
    Red,
    green

    Edit: Am I supposed to ask a question?

    Anyways, what are the properties and uses of esters.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by NightStrider)
    This is done by adding the alcohol in the presence of an acid catalyst (I think conc Sulfuric)
    By adding an acid with a carboxylic acid in the presence of an acid catalyst I believe
    Offline

    3
    ReputationRep:
    (Original post by NightStrider)
    This is done by adding the alcohol in the presence of an acid catalyst (I think conc Sulfuric)
    Almost, its done by adding an alcohol to an carboxylic acid in the presence of an sulfuric acid catalyst
    Offline

    1
    ReputationRep:
    (Original post by NightStrider)
    Crimson,
    Yellow,
    lilac,
    Red,
    green

    Edit: Am I supposed to ask a question?

    Anyways, what are the properties and uses of esters.
    It's a revision game for anyone, don't mind who answers my questions.

    Properties:
    - smell nice,
    - volatile,
    - flammable,
    - don't mix very well with alcohol, however they do with alcohols and other organic solvents.

    Uses:
    - perfumes,
    - flavourings and aromas,
    - ointments,
    - solvents.


    Q: What are the industrial conditions for the Haber Process?
    Offline

    3
    ReputationRep:
    esters can be used in artificial flavours and essences
    Offline

    3
    ReputationRep:
    (Original post by Captain Anonymous)
    Kill3r yep, your method is fine with the alcohols and fuels (i done this as well)
    Thanks!
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    Almost, its done by adding an alcohol to an carboxylic acid in the presence of an sulfuric acid catalyst
    Isnt that what I said? The spec says presence of "an acid catalyst" - it doesn't specify.
    Offline

    3
    ReputationRep:
    Why is the Haber process carried out at 200 atm, 450'C temperature and with an iron catalyst?
    Offline

    0
    ReputationRep:
    (Original post by Captain Anonymous)
    Why is the Haber process carried out at 200 atm, 450'C temperature and with an iron catalyst?
    The high pressure gives a good yield as the reaction producing ammonia forms less molecules, but it is a compromise between yield and cost as the pressure increases the cost due to stronger pipes etc being needed.

    The temperature is a compromise between yield and rate of reaction. As the reaction producing ammonia is exothermic, lowering the temperature would provide the maximum yield but it would result in far too low a rate of reaction. Thus, 450 degrees is used to get a reasonable yield with a good rate of reaction.

    The catalyst is used to speed up the rate at which equilibrium is reached.
    Offline

    3
    ReputationRep:
    (Original post by NightStrider)
    The high pressure gives a good yield as the reaction producing ammonia forms less molecules, but it is a compromise between yield and cost as the pressure increases the cost due to stronger pipes etc being needed.

    The temperature is a compromise between yield and rate of reaction. As the reaction producing ammonia is exothermic, lowering the temperature would provide the maximum yield but it would result in far too low a rate of reaction. Thus, 450 degrees is used to get a reasonable yield with a good rate of reaction.

    The catalyst is used to speed up the rate at which equilibrium is reached.
    well done, you got everything bang on
    Offline

    3
    ReputationRep:
    Define the term 'magnetic field'
    Offline

    0
    ReputationRep:
    Hi; if anyone has any links for English literature and language papers for GCSES can you plz giv us the link [l>
 
 
 
Poll
Which web browser do you use?

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.