A rigid tank with a volume of 1 m 3 contains nitrogen gas at

A rigid tank with a volume of 1 m 3 contains nitrogen gas at 600 kPa and 400 K. 1/2-kg of the gas flows out. If the final temperature is 375 K and assuming that nitrogen is an ideal gas, what is the final pressure?

I need a step by step solution.

Solution

using ideal gas law:

Initially:

no. of moles = m/Mw

m = PV*Mw/RT

m = 600*10^3*1*28/(8.314*400)

m = 5.051 kg

Now, 0.5 kg gas flows out

m1 = 5.051 - 0.5 = 4.551 kg

P = mRT/V*Mw

P = 4.551*8.314*375/28 = 506.74 kPa