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Homework Help: Helpp with thermodynamics and specific heat question!

  1. Jan 16, 2010 #1
    For an ideal monatomic gas, the molar specific heat at constant volume,
    Cv=3/2R, where R is the gas constant. The heat capacity at constant volume of a gas is measured to be 43.58kJK-1. How many kg-moles of the gas are present?




    Iv tried looking in the lecture notes and in the textbook, but cant find anything of use.

    Iv made an attempt and got 3.5kg-moles. Not sure that its right though. I used R=kNA, where k is Boltzmann constant and NA is Avogadros number.
     
  2. jcsd
  3. Jan 16, 2010 #2

    Andrew Mason

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    The heat capacity of n moles is n times the molar heat capacity.

    The heat capacity of one mole of gas at constant volume is that amount heat flow required to raise the temperature one degree:

    [tex]C_v = Q/\Delta T[/tex]

    If there are n moles, multiply both sides by n to determine the amount of heat flow per degree of temperature change.

    AM
     
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