Crystallisation

1. Pour the solution into an evaporating dish and gently heat the solution. Some of the solvent will evaporate and the solution will get more concentrated.

2. Once some of the solvent has evaporated, or when you see crystals start to form (the point of crystallisation), remove the dish from the heat and leave the solution to cool

3. The salt should start to form crystals as it becomes insoluble in the cold, highly concentrated solution

4. Filter the crystals out of the solution, and leave them in a warm place to dry. You could also use a drying oven or a desiccator.

Evaporation

1. Pour the solution into an evaporating dish.

2. Slowly heat the solution. The solvent will evaporate and the solution will get more concentrated. Eventually, crystals will start to form.

3. Keep heating the evaporating dish until all you have left are dry crystals.

Filtration

1. Grind the mixture to make sure the salt crystals are small, so will dissolve easily.

2. Put the mixture in water and stir. The salt will dissolve, but the sand won't.

3. Filter the mixture. The grains of sand won't fit through the tiny holes in the filter paper, so they collect on the paper instead. The salt passes through the filter paper as it's part of the solution.

Evaporate the water from the salt so that it form dry crystals.

Paper Chromatography

1. Draw a line near the bottom of a sheet of filter paper. (use a pencil to do this ~ pencil marks are insoluble and won't dissolve in the solvent)

2. Add a spot of the ink to the line and place the sheet in a beaker of solvent, e.g water.

3. The solvent used depends on what's being tested. Some compounds dissolve well in water, but sometimes other solvents, like ethanol, are needed.

4. Make sure the ink isn't touching the solvent - you don't want it to dissolve into it.

5. Place a lid on top of the container to stop the solvent evaporating

6. The solvent seeps up the paper, carrying the ink with it.

7. Each different dye in the ink will move up the paper at a different rate so the dyes will separate out. Each dye will form a spot in a different place - 1 spot per dye in the ink.

8. If any of the dyes in the ink are insoluble (won't dissolve) solvent you've used, they'll stay on the baseline.

9. When the solvent has nearly reached the top of the paper, take the paper out of the beaker and leave it to dry.

The end result is a pattern of the spots called a chromatogram.

Distillation

1. Simple distillation is used for separating out a liquid from a solution.

2. The solution is heated. The part of the solution that has the lowest boiling point evaporates first.

3. The vapour is then cooled, condenses (turns back into a liquid) and is collected.

4. The rest of the solution is left behind in the flask.

5. You can use simple distillation to get pure water from seawater. The water evaporates and is condensed and collected. Eventually you'll end up with just the salt left in the flask.

6. The problem with simple distillation is that you can only use it to separate things with very different boiling points - if the temperature goes higher than the boiling point, they will mix again.

7. If you have a mixture of liquids with similar boiling points you need Pure distilled water another method to separate them

Fractional Distillation

1. If you've got a mixture of liquids you can separate it using fractional distillation.

2. You put your mixture in a flask fractionating column on top. Then you heat it

3. The different liquids will all have different boiling points - so they will evaporate at different temperatures.

4. The liquid with the lowest boiling point evaporates first. When the temperature on the thermomet matches the boiling point of this liquid, it will reach the top of the column.

5. Liquids with higher boiling points might also start to evaporate. But the column is cooler towards the top. So they will only get part of the way up before condensing and running back down towards the flask

6. When the first liquid has been collected, you raise the temperature until the next one reaches the top.