Suppose that 4.7 moles of a monatomic ideal gas (atomic mass = 8.5 × 10^-27 kg) are heated from 300K to 500K at a constant volume of 0.47 m^3. It may help you to recall that CVCV = 12.47 J/K/mole and CPCP = 20.79 J/K/mole for a monatomic ideal gas, and that the number of gas molecules is equal to Avagadros number (6.022 × 10^23) times the number of moles of the gas.

Question

Suppose that 4.7 moles of a monatomic ideal gas (atomic mass = 8.5 × 10^-27 kg) are heated from 300K to 500K at a constant volume of 0.47 m^3. It may help you to recall that CVCV = 12.47 J/K/mole and CPCP = 20.79 J/K/mole for a monatomic ideal gas, and that the number of gas molecules is equal to Avagadros number (6.022 × 10^23) times the number of moles of the gas.
1) How much energy is transferred by heating during this process?
2) How much work is done by the gas during this process?
3) What is the pressure of the gas once the final temperature has been reached?
4) What is the average speed of a gas molecule after the final temperature has been reached?
5) The same gas is now returned to its original temperature using a process that maintains a constant pressure. How much energy is transferred by heating during the constant-pressure process?
6) How much work was done on or by the gas during the constant-pressure process?

Chanz · Accepted Answer

1) Q = nc*change T (c = 12.47) 2) No vol change, no work 3)P1/T1 = P2/T2 4) Use 3/2kT = 1/2mv^2 5) Q = nc*change T (c = 20.79) 6) Find new volume, W =P*changeV

Duy · Answer

For 2 and 5, draw a PV diagram. 2) Isochoric process so we have a vertical line 5) Isobaric process so we have a horizontal line