Recent content by dhoyda

the heat capacity is a function of temperature. Pretty easy integration. its like. Cp/R = A + BT + CT^2. Where A, B, C are constants.

but I thought that if a process is reversible. no work is done because it goes back to its original state. but then i remember that free expansion of gas is an irreversible process so the process can't be reversible. I feel like I am going in circles.

so basically the work from a reversible adiabatic process in an ideal gas with a non constant heat capacity is the same as the work in an irreversible process in an ideal gas with a non constant heat capacity

this is confusing. It is an irreversible process. I do not have a constant heat capacity. We defined in class a reversible work formula for adiabatic conditions with a constant heat capacity. How do I use that if my heat capacity is not constant.

did I figure it out Andrew that internal energy is equal to work and we can say dU = C*dT for Ideal gas.

the temperature is changing. I don't see how you can do that. I think I figured it out. From the first law. dU = dQ + dW. If its adiabatic the dQ = 0 and dU = dW. We can say dU = C*dT for an ideal gas.

Change in volume would be determined by the Ideal Gas law. Would you replace P with nRT/V? In this case what is constant because the gas is going to new temperature and volume. Is Temp constant when you replace P?

1. Propane vapour (1kmol) at a pressure of 40 bar and 230 C expands adiabatically to 0.25 bar and 95 C. Determine a)W, b)Delta S, c)The amount of work obtained if the expansion were done reversibly from the same initial conditions to the final pressure of 0.25bar 2. I am not sure how to...

Lets say we have a gas under pressure in a cylinder with my hand on the piston. I let my hand go and the piston shoots off the cylinder and the gas escapes to the atmosphere. I take that same arrangement of gas in the cylinder under a piston and I arrange a scenario so that the gas expands...