An open flask sitting in a lab fridge looks empty, but it is filled with a mixture of gases called air. If the flask volume is 2.50 L, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

1 Answer
Nov 2, 2016

If we assume that the temperature inside the fridge is 55 ""^@CC, there are 0.219*molxx6.022xx10^23*mol^-10.219mol×6.022×1023mol1 of dinitrogen and dioxygen molecules.

Explanation:

From the Ideal Gas Law: n=(PV)/(RT)n=PVRT == (1*atmxx5*L)/(0.0821*L*atm*K^-1*mol^-1xx278*K)1atm×5L0.0821LatmK1mol1×278K == 0.219*mol0.219mol

And thus we mulitply 0.219*mol0.219mol by "Avogadro's number"Avogadro's number.

0.219*molxx6.022xx10^23*mol^-1=??0.219mol×6.022×1023mol1=??

If the flask were at room temperature, would it contain the same number of molecules?