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Ocr a2 chemistry - f325 *unofficial mark scheme/answers* Watch

  • View Poll Results: How did you find F325 of 2016 in compared to previous years?
    Extremely harder than usual
    1.47%
    A bit more difficult than usual
    32.35%
    Similar/Average paper
    55.88%
    Easier than usual
    10.29%

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    Here's a rushed answers from the F325 paper. My Chemistry teacher allowed us to use it for half an hour and we quickly rushed every answer we could remember. 2-3 questions are missing due to the rush. We'll update the thread with the answers. I'm not too sure about them so I will update when I am.


    Please update if there's any mistakes or alternative answers, I'll try to update this post asap.

    Good luck.

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    Vote for the poll honestly to allow us to see how people found the exam in general.
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    U said questions are missing but that looks like most of them to me . Have u uploaded them all now?
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    Do you have anymore answers?
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    (Original post by Ezexamsalltheway)
    U said questions are missing but that looks like most of them to me . Have u uploaded them all now?
    I meant some answers to some of the questions are missing. Every question is there.
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    (Original post by OCRScience)
    I meant some answers to some of the questions are missing. Every question is there.
    you know that q on the pH of water, everyone said it was alkaline, but on your paper it said it was acidic? Why is that the case?
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    (Original post by mercuryman)
    you know that q on the pH of water, everyone said it was alkaline, but on your paper it said it was acidic? Why is that the case?
    Thats what my class worked out. Can you show proof on how its alkaline? If I'm honest, I got alkaline too but the majority of my class said Acidic.
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    (Original post by OCRScience)
    Thats what my class worked out. Can you show proof on how its alkaline? If I'm honest, I got alkaline too but the majority of my class said Acidic.
    TBh I'm not sure how you get alkaline, I never really understood the question. I got a pH of 6 kw(60 deg)/ 1x10^-7

    and I thought this meant the pH was acidic

    but i do believe alkaline was right. The majority say it is alkaline
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    (Original post by mercuryman)
    TBh I'm not sure how you get alkaline, I never really understood the question. I got a pH of 6 kw(60 deg)/ 1x10^-7

    and I thought this meant the pH was acidic

    but i do believe alkaline was right. The majority say it is alkaline

    Your correct, it is Alkaline. if your pH is 6 that means that is when its neutral. The question asked at a pH of 7 what would it be? If your neutral point is 6, 7 is higher than 6 so it is slightly alkaline.
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    guys, you were given the pH, so from this, you work out the H+ conc. Then you rearrange this, and using the kw value, you work out the conc of OH- . The conc of OH- was higher than the conc of OH-, therefore making it alkaline, does that make any sense?
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    (Original post by jadder1224)
    guys, you were given the pH, so from this, you work out the H+ conc. Then you rearrange this, and using the kw value, you work out the conc of OH- . The conc of OH- was higher than the conc of OH-, therefore making it alkaline, does that make any sense?
    This is what I did, likely to be the correct answer.
 
 
 
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