A 2.0 L sample of carbon monoxide gas was collected in a 2.0 L flask by displacing water at 28 °C and 108 kPa. Calculate the number of CO molecules in the flask. The vapor pressure of water at 28 °C is 3.77 kPa.
We can use here the ideal gas equation:
"PV = nRT"
Hence, After putting the given value we get the value of number of molecules.