# As water freezes to ice does its volume decrease or increase? Does the mass decrease or increase?

Jan 7, 2017

Its volume increases on freezing............

#### Explanation:

How to remember this? Consider the fate of the $\text{Titanic}$. Ice bergs float. Of course, an object will be more buoyant in salt water than in freshwater, however, when you add an ice cube to your gin and tonic, the ice cube floats (and interestingly gins are less dense than water, whereas most rums are more dense; tonics and other soft-drinks are more dense than water).

That the solid phase of water is LESS dense than the liquid phase, is a highly unusual material property, and shared by very few other materials (and none that I can think of offhand!).

As to the mass, of course mass is a constant. $10 \cdot g$ of water will give $10 \cdot g$ of ice upon freezing, and also $10 \cdot g$ of steam upon boiling.