Pure water freezes at 0°C and boils at 100°C. Would tap water likely freeze and boil at those exact temperatures? Why or why not?

May 24, 2018

Recall the colligative properties of freezing point depression and boiling point elevation.

In proportion to the molality product of the solute, ($i m$), the boiling point will raise and the freezing point will decrease.

Now, consider tap water. You know this!

Is tap water pure water? Of course not! It's a solution of many ions of metals or other inorganic compounds.

Hence, it has a varied boiling and melting point, by definition.