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    Hi, so I was doing a past paper questions and I kept getting stuck on these type of questions (the past papers are in the links below).
    I'm stuck on May 2013- Q8d) and May 2012- Q7e)ii)

    https://drive.google.com/open?id=0B_...TdMQThmazg3M0k
    https://drive.google.com/open?id=0B_...29Xd2VxZnFmRVk

    I'm not sure what equation i need to use to work it out because there's so many to do with volume and gases...? I have looked at the mark schemes for it, but i still don't understand the thinking process behind it.

    Especially May 2012- Q7e)ii) It's given the mass of Mg needed to produce it, so I thought you must have needed to use it to work it out, but according to the mark scheme, you end up working out the moles of acid instead?

    So, if someone could explain it to me, that'd be great. Thank you
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    (Original post by 1DMinHoFTHongKi)
    Hi, so I was doing a past paper questions and I kept getting stuck on these type of questions (the past papers are in the links below).
    I'm stuck on May 2013- Q8d) and May 2012- Q7e)ii)

    https://drive.google.com/open?id=0B_...TdMQThmazg3M0k
    https://drive.google.com/open?id=0B_...29Xd2VxZnFmRVk

    I'm not sure what equation i need to use to work it out because there's so many to do with volume and gases...? I have looked at the mark schemes for it, but i still don't understand the thinking process behind it.

    Especially May 2012- Q7e)ii) It's given the mass of Mg needed to produce it, so I thought you must have needed to use it to work it out, but according to the mark scheme, you end up working out the moles of acid instead?

    So, if someone could explain it to me, that'd be great. Thank you
    https://youtu.be/HKK0HD-2Igc
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    (Original post by 1DMinHoFTHongKi)

    Especially May 2012- Q7e)ii) It's given the mass of Mg needed to produce it, so I thought you must have needed to use it to work it out, but according to the mark scheme, you end up working out the moles of acid instead?

    So, if someone could explain it to me, that'd be great. Thank you
    Using the values from experiment A, you see that with ten times the amount of magnesium the acid is now the limiting reagent and the magnesium is in excess.

    Use the quantities of acid from A to show that the maximum volume of gas that could be produced is 120 ml
 
 
 
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