Avogadro's Law states that the same volume of two different gases (at the same temperature and pressure) contains the same number of particles. I understand that this hypothesis was first suggested after Gay-Lussac's experiments with electrolysis showed that the volumes of hydrogen and oxygen related at whole-number ratios.(adsbygoogle = window.adsbygoogle || []).push({});

But I don't understand how Avogadro's Law makes any sense. Could someone please explain why, for an ideal gas, Avogadro's Law is true?

For the sake of progress I'll take a stab at why it works, although I feel like I'm venturing into dangerous territory (I am not at all familiar with the kinetic theory of gases).

So here's goes: Avogadro's Law implies that each particle of gas moves freely through a surrounding volume that is the same for every existing gas molecule or atom, i.e. the amount of space that a hydrogen molecule "occupies" around it through its random movements is the same as the amount of space a nitrogen molecule occupies. This is because the smaller atom, bound less by inertia, moves faster than the larger atoms; the speed with which the particle moves varies inversely with the mass. The varying of the mass stabilizes the collision rate. Since the pressure and temperature are also the same, the same number of particles of two different gases will expand to the same volume.

Please correct what's wrong with my guess, or tell me if it's completely off.

Thanks in advance,

Zech

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# Homework Help: Avogadro's Law and Ideal Gases

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