Filtration and Crystallisation Flashcards
What is filtration used for?
For separating an insoluble solid from a liquid reaction mixture.
How do you carry out filtration?
Put filter paper into a funnel and pour your mixture into it. The liquid part of the mixture runs through the paper, leaving behind a solid residue.
How do you crystallise a product?
1) Pour the solution into an evaporating dish and gently heat the solution. Some of the water will evaporate and the solution will get more concentrated.
2) Once some of the water 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 (a desiccator contains chemicals that remove water from the surroundings).