We are given with conditions on temperature, pressure and volume of gas. In this problem, we apply ideal gas law PV = nRT to solve what are asked.
1. PV = nRT ; n = m/MM
16.5 x10^6 Pa 0.003785 m3= n 8.314 Pa m^3/ mol K (23+273) K
n = 25.38 mol; mass = 812.08 grams.
2. V at STP is 22.4 L/mol
3. PV = nRT = 1.5 atm 0.003785 1000 L = 25.38 mol 0.0821 L atm/mol K T ; T = 2.72 K
4. P 55 m3/1000 = 25.38 mol 8.314 Pa m^3/ mol K (24+273) K
P = 1139. 45 kPa