Question

Two vessels of the same size are at thesame temperature. One of them contains 1 kgOf hydrogen (molecular weight 2) and theother contains 1 kg of nitrogen (molecularweight 28)2.exasa) Which of the vessels contains moremolecules?b) In which vessel is the averagemolecular speed greater? How manytimes greater?c) Which of the vessels is at higherpressure? Why?

Answer 1

Firstly the volume and temperature is irrelevant since you have specified equal mass. Thus the ratio of numbers of atoms is the inverse of the ratio of the atomic weights of hydrogen and helium. For the ratio of molecules you must double the hydrogen atomic weight to get its molecular weight.

Ratio of Atoms 1.008 : 4.002602 so the ratio is 1/(4.002692/1.008) or 0.252

There are roughly four times as many hydrogen atoms as helium atoms, in terms of molecules the numbers are roughly two times more hydrogen molecules than helium atoms.