Problem 19.63 One type of gas mixture used in anesthesiology is a 50%/50% mixtur
ID: 1327401 • Letter: P
Question
Problem 19.63 One type of gas mixture used in anesthesiology is a 50%/50% mixture (by volume) of nitrous oxide (N20) and oxygen (02), which can be premixed and kept in a cylinder for later use. Because these two gases don't react chemically at or below 2000 psi, at typical room temperatures they form a homogeneous single gas phase, which can be considered an ideal gas. If the temperature drops below - 6 C, however, N20 may begin to condense out of the gas phase. Then any gas removed from the cylinder will initially be nearly pure 02; as the cylinder empties, the proportion of 02 will decrease until the gas coming from the cylinder is nearly pure N20. In a test of the effects of low temperatures on the gas mixture, a cylinder filled at 32.0 C to 2000 psi (gauge pressure) is cooled slowly and the pressure is monitored Part A What is the expected pressure at -5.00C if the gas remains a homogeneous mixture?Explanation / Answer
apply the formula
P2/P1 = T2/T1
T2 = -5+273 = 268 K
T1 = 273+32 = 305 K
P1 = 2000 psi
P2 = ?
P2 = (T2/T1)*P1 = (268/305)*2000 = 1757.4 = 1760 psi