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    Find the volume of ethyne (C2H2) that can be prepared from 10.0g of calcium carbide at 20C and a pressure of 100kPa.
    The answer is meant to be 0.00380m3 but I don't get this answer.
    I did:
    V=nrt/p
    N ?
    R 8.31
    T 100000
    P 273
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    (Original post by 11ashh)
    Find the volume of ethyne (C2H2) that can be prepared from 10.0g of calcium carbide at 20C and a pressure of 100kPa.
    The answer is meant to be 0.00380m3 but I don't get this answer.
    I did:
    V=nrt/p
    N ?
    R 8.31
    T 100000
    P 273
    First, you have the numbers for T and P the wrong way round !
    Secondly, 20oC is 293Kelvin (not 273K)

    After that you have to work out how many moles are in 10.0grams of calcium carbide and then use

    CaC2 + 2H2O --> C2H2 + Ca(OH)2

    To work out how many moles of ethyne this will produce, once you've done that then use V= nRT/ p to get the answer
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    (Original post by 11ashh)
    Find the volume of ethyne (C2H2) that can be prepared from 10.0g of calcium carbide at 20C and a pressure of 100kPa.
    The answer is meant to be 0.00380m3 but I don't get this answer.
    I did:
    V=nrt/p
    N ?
    R 8.31
    T 100000
    P 273
    pV=nRt
    so
    V=\dfrac{nRt}{p}
    t=20+273=293
    R=8.31
    p=100,000

    mol=\dfrac{m}{mr}

    so mol=\dfrac{10}{12+12+1+1} =n

    i'm sure you can finish the rest
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    (Original post by MexicanKeith)
    First, you have the numbers for T and P the wrong way round !
    Secondly, 20oC is 293Kelvin (not 273K)

    After that you have to work out how many moles are in 10.0grams of calcium carbide and then use

    CaC2 + 2H2O --> C2H2 + Ca(OH)2

    To work out how many moles of ethyne this will produce, once you've done that then use V= nRT/ p to get the answer
    Thank you! I've just started my A levels and I have so many calculations to do for homework it starts to confuse me!
 
 
 
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