Distillation Flashcards
What is distillation?
Distillation is a technique used to separate mixtures which contain liquids.
What is simple distillation?
Simple distillation is used to separate out a liquid from a solution.
How do you perform simple distillation?
1) Put a solution into a flask. Place a thermometer at the top to measure the temperature.
2) Heat your solution. The part of the solution that has the lowest boiling point evaporates first.
3) The vapour is cooled, condenses and goes through a condenser to be collected.
4) The rest of the solution is left behind in the flask.
What can you do to seawater with simple distillation?
You can separate pure water from it.
What is a problem with simple distillation?
You can only use it to separate things with very different boiling points.
How can you separate a mixture of liquids with similar boiling points?
You can do this by using fractional distillation.
How do you perform fractional distillation?
1) Put your mixture in a flask and put a fractionating column on top of it. After you’ve done that, heat it.
2) The different liquids all have different boiling points - so they will evaporate at different temperatures - so use a thermometer to record the temperature.
3) The liquid with the lowest boiling point will evaporate first. When the temperature matches the boiling point of the liquid, it will reach the top of the column eventually condensing. It will go through the condenser and collected.
4) Liquids with higher boiling points will start to evaporate. However, at the top of the column it is cool so the liquid will get only a bit of the way up before condensing and going straight back down to the flask.
5) When the first liquid has been collected , raise the temperature until the next liquid reaches the top.
What is a feature about the top and bottom of a fractionating column?
At the top it is the coolest it can be, but at the bottom it is the hottest part.
What does the condenser look like.
It is a tube that collects collects condensing liquids that has water out at the front and water in at the end.
