Dry nitrogen is pumped into a glove box to protect an oxygen-sensitive experiment inside. The box is maintained at a slight positive gauge pressure of 6 in. H2O to prevent air from back-diffusing into the box through a vent line. Let's say we connect the box to a standard-size gas cylinder (1.75 ft3 - initially filled to 3000 psia N2).
If the gas contents of the box must be replaced every 10 minutes and the box is 1 m3 (sitting in a 25 °C lab), how much N2 flow is required in g / min? How long will the gas bottle last? Perform your calculations assuming that nitrogen is:
(a) An ideal gas.
(b) A real gas that follows the SRK equation of state.
(c) A real gas that follows the compressibility charts.