Question

How many molecules are in 4.5 L of `CO_2` at STP?

Answer 1

`(4.5*L)/(22.4*L*mol^-1)` `xx` `N_A`, where `N_A =" Avogadro's number"`

Explanation:

We assume ideality, and recall that at `"STP"` 1 mole of ideal gas occupies a volume of `22.4*L`. We also know that `N_A =" Avogadro's number"` `=` `6.02214xx10^23*mol^-1`

So `(4.5*L)/(22.4*L*mol^-1)` `xx` `6.02214xx10^23*mol^-1` `=`

`"approx. "1/5xxN_A?`

You can do the arithmetic.

How many atoms are there in this quantity?