Question

How many atoms of helium gas are in 22.4 L at STP?

Answer 1

`"There is a ONE MOLE quantity of helium atoms....."`

Explanation:

A volume of `22.4*L` gas under standard conditions of temperature and pressure `(1*atm, 273.15*K)` specifies a MOLAR quantity of gas. That is there are `6.022xx10^23` individual helium atoms. How many individual atoms if we changed the identity of the gas to dinitrogen or dioxygen?