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    1. What is the name given to the number of molecules in one mole of CO2?
    No idea is it the avagadros number only just start as chemistry i find it hard and the questions confusing please help

    2. Hydrogen can be made by the reaction of hydrochloric acid with magnesium according to the equation

    2HCL + Mg = MgCl2 + H2

    What mass of hydrogen is formed when 100cm^3 of hydrochloric acid of concentration 5 mol dm^3 reacts with an excess of magnesium?


    I did conc*volume =moles so
    5*0.1 = 0.5 moles of hcl in 100cm^3
    HCL : Mg 2:1 ratio 0.5/2 = 0.25 moles of Mg excess
    then i am stuck (not sure about the next bit)

    is it MgCL22 1:1 ratio so there are 0.25 moles in h2
    moles*mr = mass so 0.25 * 2= 0.5g
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    dont think that is going to help
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    yes thats right

    0.5g of hydrogen gas produced, well done!!

    and its avogadros constant for number 1
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    (Original post by coursework.info)
    Need more help? You could get help with this question at Coursework.Info
    Dear Mr.coursework.info, stop the silly spamming. Or i have to say it. 0wn3d!
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    I don't know what you are worried about ^^ 0.5 grams is right and the number is called Avogadro's Number.
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    Oh good thanks
 
 
 

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