Pure N2 gas at 1atm and 25C is flowing through a 10 -m-long, 3-cm-inner diameter pipe made of 1-mm-thick rubber. Determine the rate at which N2 leaks out of the pipe if the medium surrounding the pipe is (a) a vacuum and (b) atmospheric air at 1atm and 25C with 21%O2 and 79%N2. (Answers: (a) 4.481010kmol/s, (b) 9.41011kmol/s )