Science and Mathematics for Engineering 6th Edition by John Bird

Exercise 6

A compressed air cylinder has a volume of $1.0 \mathrm {~m} ^ { 3 }$ and contains air at a temperature of $24 ^ { \circ } \mathrm { C }$ and a pressure of $1.2 \mathrm { MPa }$ . Air is released from the cylinder until the pressure falls to $400 \mathrm { kPa }$ and the temperature is $18 ^ { \circ } \mathrm { C }$ . Calculate (a) the mass of air released from the container, and (b) the volume it would occupy at S.T.P. Assume the characteristic gas constant for air to be $287 \mathrm {~J} / \mathrm { kg }$ $K$ )