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    What book is everyone using to revise from?

    I have the CGP revision guide and the OCR oxford uni. press textbook: which one would be better?
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    (Original post by benwalters1996)
    is there any way of figuring out which is exo and which is endo?

    Thats what I was thinking
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    (Original post by Red Fox)
    Got 69/85 on the specimen paper with a consistent 21 marks on each module. Feeling very confident of an A* now.
    Did you get Qu8?? As I am looking at it and I can't seem to do it (the one with the titrations)

    question 8) b) if you do get could you please explain? Thanks
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    (Original post by benwalters1996)
    is there any way of figuring out which is exo and which is endo?
    (Original post by dazzer19)
    Did you get Qu8?? As I am looking at it and I can't seem to do it (the one with the titrations)

    question 8) b) if you do get could you please explain? Thanks
    They will tell you which reaction is exo/endothermic. For question 8b you just take about how universal indicator would slowly change depending on pH instead of an instant change at the end point like litmus.
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    Why is it easier for hydrogen ions to be discharged not sodium in electrolysis of naOH. So like how will we know what the products will be?
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    (Original post by Red Fox)
    Got 69/85 on the specimen paper with a consistent 21 marks on each module. Feeling very confident of an A* now.
    so you only got 6 on section D?
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    (Original post by Red Fox)
    They will tell you which reaction is exo/endothermic. For question 8b you just take about how universal indicator would slowly change depending on pH instead of an instant change at the end point like litmus.

    Oopw, I meant 8c haha, I got 8b :P I just can't figure out 8c
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    (Original post by L'Evil Fish)
    C4 Six Marked on the additional was on the history of periodic tables...
    so that CERTAINLY won't come up as one of ours right?.......................... .....
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    (Original post by benwalters1996)
    so you only got 6 on section D?
    Yep
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    (Original post by Turtlefushsia)
    Why is it easier for hydrogen ions to be discharged not sodium in electrolysis of naOH. So like how will we know what the products will be?
    Thatd a level stuff, it's to do with their values... We'll get told I think?

    But we should know them for the examples given.
    (Original post by benwalters1996)
    so that CERTAINLY won't come up as one of ours right?.......................... .....
    Highly doubt it
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    L'evil Fish- some of your comments are highly advanced...are you doing A-levels??...or just very good at chemistry and wider reading
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    (Original post by dazzer19)
    Oopw, I meant 8c haha, I got 8b :P I just can't figure out 8c
    I'll try to explain it. You want the concentration of nitric acid so you know you're going to have to use the formula concentration=number of moles/volume. You can work out the number of moles of nitric acid by calculating how many moles of potassium hydroxide you have since it is a 1:1 ratio. Use number of moles= concentration x volume to work out there are 0.0025 moles of KOH hence there must be 0.0025 moles of HNO(3). Now you have the number of moles you just need the volume, this can be worked out from the titration table on the previous page. You ignore number 1 as it is not concordant with number 2 and 3. Using them you get a mean titre of 20cm^3(0.02dm^3). You plug the volume (mean titre, 0.02dm^3) and the number of moles (0.0025) into the concentration formula to get 0.125 mol/dm^3. Sorry for the large amount of writing but that's the best help I can give.
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    (Original post by Red Fox)
    I'll try to explain it. You want the concentration of nitric acid so you know you're going to have to use the formula concentration=number of moles/volume. You can work out the number of moles of nitric acid by calculating how many moles of potassium hydroxide you have since it is a 1:1 ratio. Use number of moles= concentration x volume to work out there are 0.0025 moles of KOH hence there must be 0.0025 moles of HNO(3). Now you have the number of moles you just need the volume, this can be worked out from the titration table on the previous page. You ignore number 1 as it is not concordant with number 2 and 3. Using them you get a mean titre of 20cm^3(0.02dm^3). You plug the volume (mean titre, 0.02dm^3) and the number of moles (0.0025) into the concentration formula to get 0.125 mol/dm^3. Sorry for the large amount of writing but that's the best help I can give.
    Thanks a lot! I was just getting very confused at they whole question!
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    (Original post by dazzer19)
    Thanks a lot! I was just getting very confused at they whole question!
    I got it wrong anyway but my teacher explained it to the class. If I got those 4 marks I would have got 25/25 on C5:mad:
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    (Original post by benwalters1996)
    L'evil Fish- some of your comments are highly advanced...are you doing A-levels??...or just very good at chemistry and wider reading
    None of the above :lol:

    Okay for concentration and neutralization questions.

    Y cm^3 of Substance A, with concentration of W mol/dm^3 is neutralized by X cm^3 of Substance B, with an unknown concentration (lets call it Z mol/dm^3(.

    Find Z:
    Substance A -
    Number of Moles = (Y/1000)(W)

    Substance B has an equal number of moles, worked out using balanced equation.

    (Y/1000)(W) = (X/1000)(Z)

    Z = \frac{\frac{wy}{1000}}{\frac{x}{  1000}}

    In a general sense ^
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    (Original post by L'Evil Fish)
    None of the above :lol:

    Okay for concentration and neutralization questions.

    Y cm^3 of Substance A, with concentration of W mol/dm^3 is neutralized by X cm^3 of Substance B, with an unknown concentration (lets call it Z mol/dm^3(.

    Find Z:
    Substance A -
    Number of Moles = (Y/1000)(W)

    Substance B has an equal number of moles, worked out using balanced equation.

    (Y/1000)(W) = (X/1000)(Z)

    Z = \frac{\frac{wy}{1000}}{\frac{x}{  1000}}

    In a general sense ^
    I'd just prefer it to do it step by step as I know I'd probably make an error if I did it that way. Have you done the specimen paper?
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    (Original post by Red Fox)
    I'd just prefer it to do it step by step as I know I'd probably make an error if I did it that way. Have you done the specimen paper?
    For those who just want to pass it and not understand :yep:

    And :erm: no. I've seen it though, I felt it was harder than bio. But manageable I hope :lol:
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    (Original post by Red Fox)
    I'd just prefer it to do it step by step as I know I'd probably make an error if I did it that way. Have you done the specimen paper?
    I didn't know there was a specimen paper, where did you get it from? I can't find it on the ocr website..
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    (Original post by L'Evil Fish)
    For those who just want to pass it and not understand :yep:

    And :erm: no. I've seen it though, I felt it was harder than bio. But manageable I hope :lol:
    It was a very easy paper, if the real exam is like that I will be a happy man
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    (Original post by Red Fox)
    It was a very easy paper, if the real exam is like that I will be a happy man
    Really? I'll have another look :mmm:
 
 
 
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