Evaporation
Science: KS3, topic 2.1.15
Evaporation
When a substance evaporates, it turns from a liquid into a vapour. Evaporation can occur naturally or by boiling the liquid.
Evaporation
- Evaporation is when a liquid is physically changed into a gas or vapour.
- Evaporation of a liquid occurs at a lower temperature than the liquid's boiling point.
- The boiling point is the temperature at which a liquid will change state.
Separating a solution
- A solution can be made by mixing copper sulphate and water.
- The water acts as the solvent and dissolves the copper sulphate.
- If you heat the solution, the water will evaporate rapidly.
- Copper sulphate does not evaporate.
- Crystals of copper sulphate will be left behind.
Evaporating naturally
- If the copper sulphate and water solution evaporates naturally, the process will take more time.
- The longer the evaporation process takes, the larger the copper sulphate crystals will be.
Test yourself on Evaporation
What is it called when a liquid is physically changed into a gas or vapour?
What do we call the temperature at which a liquid will change state?
Select the correct statement in each pair
A puddle of rainwater dries up on a warm day, even though the air temperature is far below water's boiling point. What is happening to the water in the puddle?
A copper sulphate solution is heated until all the water has evaporated. Why are copper sulphate crystals left behind in the container?