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    I really don't get this equation and how to rearrange it. Can somebody help?
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    (Original post by AndrewKn0x)
    I really don't get this equation and how to rearrange it. Can somebody help?
    I am assuming you are talking about PV = nRT right?

    The equation comes from gas laws. Boyle's Law and Charles' Law and the Pressure Law. Basically if you have a ideal gas in one situation and the another situation the three things that can change are Pressure, Volume and Temp. (Fixed mass of gas so mol doesn't change).

    Rearranging PV = nRT we get PV/T = nR (nR is a constant because they stay the same).

    So in two situations P1 V1 / T1 = nR and P2 V2 / T2 = nR
    Since nR is the same in both situations we can equate the two to get your equation:

    P1 V1 / T1 = P2 V2 / T2

    Example Question: A gas in a box is at 290K. The pressure of a gas is 2.0X105 Pa and the Volume is 1x10-3 m3. The temperature of the box is increased to 390K whilst the Volume remains the same. What is the pressure of the gas now?

    P1 = 2.0X105 V1 = 1x10-3 T1 = 290

    P2 = ??? V2 = 1x10-3 T2 = 390


    2.0x105 x 1x10-3 / 290 = P2 x 1x10-3 / 390

    Simplify up we get:

    0.6897 = P2 x 2.5641x10-6

    Therefore P2 = 0.6897 / 2.5641x10-6 = 2.7x105 Pa

    Hope that helps
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    (Original post by sirraza97)
    i am assuming you are talking about pv = nrt right?

    The equation comes from gas laws. Boyle's law and charles' law and the pressure law. Basically if you have a ideal gas in one situation and the another situation the three things that can change are pressure, volume and temp. (fixed mass of gas so mol doesn't change).

    Rearranging pv = nrt we get pv/t = nr (nr is a constant because they stay the same).

    So in two situations p1 v1 / t1 = nr and p2 v2 / t2 = nr
    since nr is the same in both situations we can equate the two to get your equation:

    P1 v1 / t1 = p2 v2 / t2

    example question: A gas in a box is at 290k. The pressure of a gas is 2.0x105 pa and the volume is 1x10-3 m3. The temperature of the box is increased to 390k whilst the volume remains the same. What is the pressure of the gas now?

    P1 = 2.0x105 v1 = 1x10-3 t1 = 290

    p2 = ??? V2 = 1x10-3 t2 = 390


    2.0x105 x 1x10-3 / 290 = p2 x 1x10-3 / 390

    simplify up we get:

    0.6897 = p2 x 2.5641x10-6

    therefore p2 = 0.6897 / 2.5641x10-6 = 2.7x105 pa

    hope that helps
    thank you so much
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    (Original post by AndrewKn0x)
    thank you so much
    No problem man
 
 
 
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