SC2d Distillation Flashcards
How can you purify water
By distillation
How distillation works
When mineral water evaporates only the water turns to a gas . The solid minerals which have much higher boiling points are left behind .
If the vapour is condensed it turns back to liquid water again . The liquid water will now be pure .
This combination of evaporation followed by condensation is called distillation . The apparatus used is called a still.
What is fractional distillation .
Distillation that is used to seperate two or more liquids
How does fractional distillation work
It works because some liquids boil more easily than others. Liquids with lower boiling points evaporate more easily than others , and will turn into a vapour first.
Ways fractional distillation is used in real life
To separate different products in crude oil.
To make alcoholic drinks such as whiskey and vodka
To seperate out the gases in the air
How an efficient fractional distillation machine works.
A column is fixed above the distillation flask . The hot vapour rises up the column . At first the vapour condenses when it hits the cool glass and drips down into the flask . As the column gradually heats up there will be a temperature gradient . It will be hottest at the bottom and the temperature will drop as you go further up the column . The fraction with the lowest boiling point will reach the top of the column first and the vapour will then pass into the lieblig condenser , if you keep heating fractions with higher boiling points will then rise up the column and can be collected later .
