I will, respectfully, disagree. The solution uses the difference between vapor volumes to find the EXACT weight that is supposedly bled off.
Logic dictates that there must be more than 72 kg added to the tank if some of it was bled off, but science does not dictate that it was exactly 3 kg...
The statement "slowly introduced" screams quasiequilibrium process. I think this is the result of revising a an old problem to be a new problem with new answers (as is commonly done when authors create new editions of their texts).
I'm going to report it as errata: it is misleading at best...
Latexman- are you saying that 75kg is the answer, merely for the fact that 75kg is larger than 72kg? Or did you actually calculate a blow off of ~3 kg of vapor? The step in the solution covering the calculation of the additional mass is very specific in that the blow off is [initial vapor...
Choices are 14kg, 22kg, 72kg, and 75kg. I guess you could say that since you bled off some gas, the amount of mass you added must be more than 72kg. Still doesn't explain why it would be exactly 75kg though...
What am I missing here???
Actually, this is not homework (but I see why you would think so). This is a problem from FE review material (a VERY popular piece of review material). The solution for the problem is given as 75kg. I don't know enough to say I agree with how that number is arrived at.
My solution, which...
Here's the problem statement:
A 0.5m^3 rigid tank has equal volumes of saturated refrigerant vapor and refrigerant liquid at 312 deg K. Additional refrigerant is then slowly introduced into the tank until the total mass of refrigerant (liquid and vapor) is 400 kg. Some vapor is bled off to...
