This document discusses evaporation and how it can be used to separate soluble solids from liquids. Evaporation involves heating a mixture until only the dissolved salts remain. It is suitable for separating one soluble solid from one liquid component. For example, table salt is obtained by evaporating sea water through heating from the sun. A thermometer also works through thermal expansion, where the liquid in the tube expands and contracts with temperature changes, allowing the calibrated lines to indicate the temperature.

1. Separation of Soluble Solids
Objectives
Standard 3
General Science

2. Evaporation
.
Evaporation is a technique used to separate out all mixtures where
there is one or more dissolved salts.
The process typically involves heating the mixture until no more
liquid remains.
Prior to using this method, the mixture should only contain one
liquid component.
This is because all liquid components will evaporate over time.
This method is suitable to separate a soluble solid from a liquid.

3. Evaporation
.

4. Evaporation
In many parts of the world, table salt is
obtained from the evaporation of sea
water. The heat for the process comes
from the sun.

5. Temperature
Thermometers take advantage of a scientific property called thermal
expansion. Most substances will expand and take up more volume as they
get hotter.
As the temperature rises, the liquid expands and fills up more of the tube.
When the temperature drops, the liquid contracts and takes up less of the
tube. The temperature can then be read by the lines calibrated on the side
of the tube.
In our everyday lives we use the word temperature to describe the
hotness or coldness of someone or something.
Temperature is measured using a thermometer.
How does a thermometer work?

6. Temperature

7. Thermometer
Liquid thermometers have some sort of
substance (this used to be mercury, but today is
generally alcohol) that is enclosed in the small
glass tube.