Determine the atomicity of oxygen by applying Avogadro's law.

Derive from the Avogadro's law that molecular mass is equal to mass of $22.4 \mathrm{litres}$ of gas or vapour at NTP.

State and explain Avogadro's law. How does it explain Gay-Lussac's law of gaseous volumes. How it could discard Berzelius's hypothesis?

Derive the relationship between molecular mass and vapour density of gas from Avogadro's hypothesis. $0.796 \mathrm{g}$ of a metal oxide was heated in a current of dry hydrogen when $0.18 \mathrm{g}$ of water was formed. Calculate the equivalent mass of the metal.

How many molecules will be present in one gram molecular mass of hydrogen gas?

How many atoms of hydrogen are present in two moles of ${\mathrm{H}}_3{\mathrm{PO}}_4$?