Question

Water has the molecular formula H₂O and has a density of 1.00g/cm³ at 25 °C. On average, what is the volume occupied by one water molecule in cm³?

Answer 1

The volume of one water molecule is `2.99 × 10^"-23" "cm"^3`.

Explanation:

First, convert the volume of water → mass of water → moles of water → molecules of water.

`1.0" g H"_2"O" × (1"cm"^3)/(1.00"g H"_2"O") × (1"mol H"_2"O")/(18.02"g H"_2"O") × (6.022 ×10^23"molecules")/(1"mol H"_2"O") =`

`3.342 × 10^22" molecules"`

Then calculate the volume of one molecule.

Volume = `(1"cm"^3)/(3.342 × 10^22"molecules")` = 2.99 × 10⁻²³ cm³/molecule