# Water can exist in each of the three states of matter (except plasma). How can you describe the volume for each state?

Aug 30, 2017

Well, volume is an extensive property, so it is not a good measure of comparison. Molar volume, $\overline{V} \equiv \frac{V}{n}$, would make more sense, as it is an intensive property, independent of sample size.

As seen here, molar volume is proportional to the reciprocal of the density. Thus, as the density of a substance increases, its molar volume decreases.

We know that the density goes as:

${D}_{\text{solid" > D_"liquid}}$ $\text{>>}$ ${D}_{\text{gas}}$

Therefore, we say that:

$\textcolor{b l u e}{\overline{\underline{| \stackrel{\text{ ")(" "barV_"solid" < barV_"liquid" " << " barV_"gas"" }}{|}}}}$