# Does pure water have a concentration?

Mar 29, 2017

There isn’t any.

#### Explanation:

By definition, “molarity” is the number of moles of a substance dissolved in a liter of solvent – which is usually water.

A pure solvent by itself does not meet the definition requirements of a “molar” solution. Theoretically you could have some molar concentration of water in a different solvent.

Mar 29, 2017

In fact we can speak of the $\text{molarity}$
or the $\text{concentration of water......}$

#### Explanation:

$\text{Molarity}$ $=$ $\text{Moles of solute (mol)"/"Volume of solution (L)}$

$= \frac{\frac{1000 \cdot g}{18.01 \cdot g \cdot m o {l}^{-} 1}}{1.00 \cdot L} = 55.2 \cdot m o l \cdot {L}^{-} 1$.

Water is concentrated stuff. With respect to moles per unit volume, it is a much more concentrated solvent than comparable systems, say $H F$, or $\text{acetic acid}$, and normally both of these materials are deployed as aqueous solutions. Given water's involatility, i.e. a boiling point of $100$ ""^@C under normal pressure, these 2 physical properties distinguish water as a REMARKABLE and UNUSUAL solvent.

What factors influence these properties?

Mar 29, 2017