1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

    User Avatar
    Science Advisor
    Homework Helper

    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.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook