More Separation Techniques Flashcards
What is filtration?
Filtration is a method of separating insoluble solids from liquids.
Explain how to do filtration?
1) Fold filter paper into a cone shape and place it above a beaker.
2) Place insoluble solids and liquids.
3) Let it do its thing and eventually the solid is left in the filter paper with the liquid in the beaker.
Name two ways you can separate soluble solids from solutions?
Evaporation and Crystallisation.
How do you perform evaporation?
1) Get a Bunsen Burner and place it below a tripod and a gauze.
2) Place the evaporating dish on the gauze.
3) Put your solution in the dish.
4) Turn your Bunsen Burner on a slowly heat the solution. The solvent will evaporate and the solution will get more concentrated.
5) Eventually, crystals will start to form. Keep heating the dish until there is only dry crystals.
How do you perform crystallisation?
1) Pour your solution in an evaporating dish and gently heat the solution. Some of it will evaporate and the solution will get more concentrated.
2) Once the solvent has been evaporated OR when crystals start to form, 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 it in a warm place to dry such as a drying oven.
What is rock salt a mixture of?
Rock salt is a mixture of sand and salt.
What methods can be used to separate rock salt?
Filtration and Crystallisation.
What is the difference between sand and salt?
Salt dissolves in water but sand doesn’t.
How do you separate rock salt?
1) Grind the mixture to make sure the salt crystals are small, so it will dissolve easily.
2) Put the mixture in water and stir it. The salt will dissolve but the sand won’t. Bear in mind, you can heat the mixture to help dissolve the salt.
3) Filter the mixture. The grains of sand won’t fit through the holes in the filter paper so they collect on the paper instead. The salt passes through the filter paper as it is part of the solution.
4) Evaporate the water from the salt so that it forms dry crystals.
