One tenth kilogram of Argon is contained in a piston-cylinder assembly. Initially at 4900 K and a volume of 40 liters, the gas undergoes an isobaric process during which the heat input is 30 kJ. Where / how do i start to determine the boundary work and final temperature
100 kg of Ar is 2.5 moles. The pressure P can be obtained from that and the ideal gas law.
P = n R T/V = 2.5 moles*8.205*10^-2 l-atm/mole K * 4900 K/40 l = 25.1 atm = 25.4*10^5 N/m^2
Constant pressure heating of Ar will have a specific heat of (5/2) R. Use that info to obtain the final temperature, T2.
Get the final volume from
V2/V1 = T2/T1
Get the work done from P*(V2-V1)
drwls ...thanks for the help you have steered me in the right direction Gary
You're welcome! I'm glad I could help steer you in the right direction. It looks like you have a good understanding of the steps involved in determining the boundary work and final temperature.
To recap, here are the steps you can follow:
1. Calculate the pressure (P) using the ideal gas law:
P = (n * R * T) / V
n = number of moles of Argon
R = ideal gas constant
T = initial temperature
V = initial volume
2. Calculate the final temperature (T2) using the specific heat capacity of Argon at constant pressure:
T2 = T1 + (Q / (n * Cp))
T1 = initial temperature
Q = heat input
Cp = specific heat capacity of Argon at constant pressure
3. Calculate the final volume (V2) using the relationship between temperature and volume:
(V2 / V1) = (T2 / T1)
V1 = initial volume
4. Determine the boundary work done by the gas during the process using the formula:
Work = P * (V2 - V1)
P = pressure
V2 = final volume
V1 = initial volume
By following these steps, you should be able to determine the boundary work and final temperature for the given isobaric process. Let me know if there's anything else I can help you with!