A 150-liter cylinder of carbon monoxide is stored in a 30.7-m³ room. The pressure gauge on the tank reads 2500 psi when the tank is delivered. Sixty hours later the gauge reads 2245 psi. The Threshold Limit Value Ceiling (TLV-C) molar concentration of CO—that is, the concentration considered unsafe for even instantaneous human exposure—is 200 ppm (200x10^-6 mol CO/mol room air).24 The temperature of the room is constant at 27°C. 

(a) The decrease in pressure is a source of concern, but it may have resulted from a reduction in the temperature of the tank as it was transported from the loading dock to the air-conditioned laboratory. Without assuming that the gas behaves ideally, show that this is unlikely to be the case. 

(b) Having determined that the pressure decrease must be due to a leak, estimate the average leak rate (mol CO/h), again without assuming that the gas behaves ideally. 

(c) Calculate t_min(h), the minimum time from delivery at which the average concentration of CO in the room could have reached the TLV-C concentration. Explain why the actual time to reach this concentration would be greater. 

(d) Why could it be disastrous to enter the room at any time without wearing proper personal protective equipment, even at a time t < t_min? (Think of at least three possible reasons.)