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Calculating mass by pressure needed to move object

  1. Jan 8, 2016 #1
    1. The problem statement, all variables and given/known data
    A cilinder is filled with 50mg of H2 gas. In the cilinder is a piston with a surface of 27cm The temperature of the gas equals 298K. The piston rises 2cm when the temperature rises 30 degrees. Calculate the mass of the piston
    Also given data:
    MH2=2.02g/mol

    Right answer: 3.6kg
    2. Relevant equations

    Ideal gas equation : p.V = n.R.T



    3. The attempt at a solution
    I though the volume rose with 2x27cm^2 = 54cm^3
    So I used the ideal gas formula and used Volume 1 as X and Volume2 as x+54 and equaled those formulas to each other but received the wrong answer.
     
  2. jcsd
  3. Jan 8, 2016 #2

    TSny

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    Hello and welcome to PF.

    You said that you "equaled those formulas to each other". Could you show the steps involved in doing this?
     
  4. Jan 9, 2016 #3

    p=nRT/V1=nRT/V2
    I calculated that n= 0,024

    (0,024.8,31.298K)/x=(0,024.8,31.328K)/(x+0,54)

    I tried to find x there and ended up with 0,56. Then I put the x back in the formula and tried to find the pressure with it. Which was 106(pa?). How to find the mass of the piston with that is still a mystery
     
  5. Jan 9, 2016 #4

    haruspex

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    if that's the pressure, what force is it exerting on the piston?
     
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