Key terms
What is a mixture?
Two or more substances not chemically combined
Which method separates an insoluble solid from a liquid?
Filtration.
What equipment is used in filtration?
Filter funnel and filter paper.
How would you separate sand and water?
Why can mixtures be separated by physical methods?
Because substances are not chemically bonded.
What is a solute?
The substance that dissolves.
Which method separates salt from saltwater?
Evaporation.
Why is the start line in chromatography drawn in pencil?
Ink would dissolve and affect results.
How would you separate pebbles from sand?
Sieving
Why does chromatography separate substances?
They travel at different speeds depending on solubility.
What is a solvent?
The liquid that dissolves the solute.
Which method is used to separate pure water from saltwater?
Distillation.
What happens to the solvent during evaporation?
It turns into a gas and leaves the solute behind.
How would you separate iron filings from sand?
Use a magnet.
What does one spot on a chromatogram show?
A pure substance.
What is a solution?
A mixture where a solute is dissolved in a solvent.
Which method separates liquids with different boiling points?
Fractional distillation.
What are the two processes in distillation?
Evaporation and condensation
How would you separate oil and water?
Decantation (pouring off layers)
Why is distillation better than evaporation for getting water?
It collects the water as well as separating it.
What is the difference between a mixture and a compound?
Mixtures are not chemically bonded; compounds are chemically bonded.
Which method separates colours in ink?
Chromatography.
What is the purpose of a condenser in distillation?
To cool gas back into liquid.
How would you separate salt, sand, and water?
Filter sand, then evaporate or distill water.
Explain why filtration cannot separate saltwater.
The salt is dissolved, so it passes through the filter.