Chemistry

Free online chemistry lesson for elementary school, middle school and high school.

 

Mixtures and solutions

Vaporization

1) Vaporization of mineral water

After the vaporization of a mineral water, some whitish compounds form in the container: these are minerals
During vaporization water changes of state but minerals keep their solid state and they form crystals

2) In which cases can a vaporization be useful ?

The vaporization can be used to recover the solid compounds dissolved in water since they are not vaporized but they return to their original solid appearance.
Example: In the salt marshes, vaporization is used to recover the salt contained in seawater.

We can therefore use the vaporization in order to get solid compounds dissolved in water like salt, minerals, sugar etc.

3) What is pure water ?

Given that the vaporisation reveals the presence of minerals, it means that water is not pure.
In chemistry we say that a substance is pure if hasn't been mixed with other substances.
If water is mixed with mineral salts it is therefore no longer pure.

Comment:
It should not be confused pure water with potable water. A potable water is a water which consumption does not represent a health risk and this does not preclude the presence of minerals that are even essential to human body.

---

---