State Gay-Lussac's law of combining volumes and Avogadro's law.

Gay-Lussac's law states that when gases react they do so in volumes that bear a simple whole-number ratio to one another and to the volumes of any gaseous products, all volumes being measured at the same temperature and pressure. Avogadro's law states that equal volumes of all gases under the same conditions of temperature and pressure contain the same number of molecules.

No citable source has been recorded for this record. Treat it as practice material, not as fact.

Explanation

Avogadro's law explains Gay-Lussac's law, because equal volumes then correspond to equal numbers of molecules.