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    (Original post by Subtlety)
    Excess isn't too bad for me, anything that involves molar volume, and "A solution of potassium chloride and potassium carbonate is known to contain 0.4 moles of chloride ions and 0.4 moles of carbonate ions. How many moles of potassium are present" just....whaaat
    Ratio of Potassium to Chlorine = 1:1, Therefore 0.4 moles of K in KCL
    Ratio of Potassium to Carbonate = 2:3, Therefore the number of moles of K is 0.4/3 * 2 = 0.27
    Therefore total number of moles of K present = 0.4 + 0.27 = 0.67 moles (If this is wrong I'm sorry )
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    (Original post by koolkate)
    I actually like multiple choice questions because you have 25% chances of getting them right. In my prelim I just randomly ticked boxes!

    I have Only done 3 PP no other subject and I am sure you have done more than that!
    eh I only don't like multiple choice if two answers are so similar, like positive and negative of same number
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    (Original post by TheFOMaster)
    Any particular questions? I can give you a step by step guide if you want?
    Oh that would be good, thank you! Questions like:

    Calculate the mass of aluminium, in grams, produced in 20 minutes when a current of 50 0000 A is used

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    (Original post by TheFOMaster)
    Ratio of Potassium to Chlorine = 1:1, Therefore 0.4 moles of K in KCL
    Ratio of Potassium to Carbonate = 2:3, Therefore the number of moles of K is 0.4/3 * 2 = 0.27
    Therefore total number of moles of K present = 0.4 + 0.27 = 0.67 moles (If this is wrong I'm sorry )
    I guess it's right haha, but how do you know the ratio's? Thanks
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    (Original post by ManicPumpkin)
    Oh that would be good, thank you! Questions like:

    Calculate the mass of aluminium, in grams, produced in 20 minutes when a current of 50 0000 A is used

    I missed class for these So I'm not amazing but:

    First calculate the charge using the relationship Q = It, remember the units are Charge (C), current (A) and time (s) in this case the Charge is 500000 * (20*60) = 6x10^9 C.

    Remember 1 Faraday of charge allows one electron to be added to an ion. 1 F = 96500C.

    Next calculate the number of Faradays required to add electrons to an ion so that its of neutral charge. For Aluminium, it's ion has a positive charge of 3. so 3 Faradays is required. This must be converted to Charge so 289500C is required for 1 mole to be deposited.

    1 mole -> 289500 C
    x moles -> 6x10^9

    Now, cross multiply and divide to find x (I get 20725.4 moles) then use g = gfm * n to get the mass deposited in grams

    (Original post by Subtlety)
    I guess it's right haha, but how do you know the ratio's? Thanks
    From the data book and valency. If an element is in group 1 to 3 its group number is its valency, if its in group 5 to 8 is 8-groupnumber. For things like carbonates and sulphates, theres a table in the data booklet, can't remember what its called, but it has table headings like one positive, one negative etc.
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    My first exam is on the 9th. Yayyy :pierre: I've studied for biology and maths, but yet to revise really for the other 3 subjects. I really want an A for Maths because my teacher hates me and it would really annoy her :giggle:
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    (Original post by TheFOMaster)
    I missed class for these So I'm not amazing but:

    First calculate the charge using the relationship Q = It, remember the units are Charge (C), current (A) and time (s) in this case the Charge is 500000 * (20*60) = 6x10^9 C.

    Remember 1 Faraday of charge allows one electron to be added to an ion. 1 F = 96500C.

    Next calculate the number of Faradays required to add electrons to an ion so that its of neutral charge. For Aluminium, it's ion has a positive charge of 3. so 3 Faradays is required. This must be converted to Charge so 289500C is required for 1 mole to be deposited.

    1 mole -> 289500 C
    x moles -> 6x10^9

    Now, cross multiply and divide to find x (I get 20725.4 moles) then use g = gfm * n to get the mass deposited in grams
    I actually sort of get that! Thanks very much! Clearly you are some sort of Chemistry mastermind...
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    (Original post by TheFOMaster)

    From the data book and valency. If an element is in group 1 to 3 its group number is its valency, if its in group 5 to 8 is 8-groupnumber. For things like carbonates and sulphates, theres a table in the data booklet, can't remember what its called, but it has table headings like one positive, one negative etc.
    Thanks man If I can get all the calculations down I'll feel infinitely better about this exam. Can't wait to never have to do chemistry again haha
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    (Original post by ManicPumpkin)
    I actually sort of get that! Thanks very much! Clearly you are some sort of Chemistry mastermind...
    Bwahahaha I'm actually in the process of trying to change my uni course away from Chemistry

    Just:
    1) Calculate the charge available
    2) Calculate the charge required for one mole
    3) Divide the charge available by the charge required
    4) Calculate the mass in grams

    And if they ask something else, such as calculate the charge available, do the steps in a different order
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    (Original post by TheFOMaster)
    Bwahahaha I'm actually in the process of trying to change my uni course away from Chemistry

    Just:
    1) Calculate the charge available
    2) Calculate the charge required for one mole
    3) Divide the charge available by the charge required
    4) Calculate the mass in grams

    And if they ask something else, such as calculate the charge available, do the steps in a different order
    Haha! Oh well

    Amazeballs! Thanks again
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    Hmm...
    My first exam is one the 9th (Modern studies) and I still need to knuckle down properly and revise. I find the content easy but have trouble with time management which let me down in the prelim.
    I'm not feeling very confident for English. My folio is predicted to score highly so that slightly lessens the pressure, but I really need to buckle down and do some CR practice as well as learn my quotes.
    History, if I thoroughly revise my essay plans/paper 2 material should go well. I scored highly in the prelim so am pretty confident about it.
    As for French and German, I feel very confident about them and I'm not going to even think about them until I've done English.
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    My first exam is Music on May 10th which should be alright. Then Maths which hopefully will be alright as well! Then English which could be interesting. I'm not worried about the close reading, just the essays as I always struggle writing within the time. I'm confident about Computing. Chemistry should also be interesting, but as long as I keep practicing my calculations I should be fine!
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    I have reached the stage where I get up around 9 every morning, revise all day, and then have to force myself to go to bed as I feel like I'm wasting revision time by sleeping. I am panicking so badly.
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    First exam is maths on 22nd of May feeling good for everything apart from PE.
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    (Original post by ManicPumpkin)
    My first exam is Music on May 10th which should be alright. Then Maths which hopefully will be alright as well! Then English which could be interesting. I'm not worried about the close reading, just the essays as I always struggle writing within the time. I'm confident about Computing. Chemistry should also be interesting, but as long as I keep practicing my calculations I should be fine!
    English is before Maths and Computing had a low boundary for the past few years I think, so if your coursework is good, you'll ace it

    (Original post by dartanoir)
    I have reached the stage where I get up around 9 every morning, revise all day, and then have to force myself to go to bed as I feel like I'm wasting revision time by sleeping. I am panicking so badly.
    Don't panic. What subjects do you do, and what do you roughly get in past papers for them? I'd tone down the studying to an hour a day, maybe 2. You'll burn yourself out come May, which won't help your performance :no:
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    (Original post by TheFOMaster)
    English is before Maths and Computing had a low boundary for the past few years I think, so if your coursework is good, you'll ace it
    :no:
    I knew English was before Maths...I was just testing you...

    My Coursework was alright. I think I got full marks for Part 2. However my program in part 1 didn't work, but I think I got 16/17 for algorithm etc. Computing is actually my best subject so it should be fine!
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    (Original post by ManicPumpkin)
    I knew English was before Maths...I was just testing you...

    My Coursework was alright. I think I got full marks for Part 2. However my program in part 1 didn't work, but I think I got 16/17 for algorithm etc. Computing is actually my best subject so it should be fine!

    What was your overall coursework award out of 60?
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    (Original post by TheFOMaster)
    Don't panic. What subjects do you do, and what do you roughly get in past papers for them? I'd tone down the studying to an hour a day, maybe 2. You'll burn yourself out come May, which won't help your performance :no:
    In order to start past papers I need to revise the curriculum and there is just so much! I am currently re taking AS French, and doing A2 french, history and english literature, as well as extended project and general studies.
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    (Original post by GreigM)
    What was your overall coursework award out of 60?
    I've not actually been given it yet but I've seen what I got for part 2, so I would say maybe 46 or 47/60
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    My first exam is on the 15th (Bio) then Maths on 22nd, Geography on the 30th and then 2 exams on the 31st (Chem and ESOL)

    I'm pretty confident about Maths and ESOL.
    Chem and Bio are alright, but Geography is a disaster... Way too many things to remember
 
 
 
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