Chapter 2: Separation techniques Flashcards
(15 cards)
What are mixtures?
Different substances found together, but not chemically bonded. This means the different substance can be separated
What is a compound?
Different substances that are chemically bonded together
What is the difference between a pure substance and an impure substance?
A pure substance has a single, sharp melting point, while an impure substance (a mixture) has a range of temperatures for its melting point
What is a solvent?
The liquid that makes up most of the solution
What is a solute?
The substance that is added to the solvent and dissolves into it
What happens to a solute over time as it’s in a solvent?
As the solute usually starts as a solid, its particles break away from each other and move into the solvent
What is solubility?
How much solute can dissolve in a certain volume of solvent
What is the difference between a soluble substance and an insoluble substance?
A soluble substance can dissolve while insoluble substances cannot
True or False. Increasing the temperature often increases the solubility
True
What does saturated mean?
When so much solute has been added to the solvent that no more can dissolve
What are four ways to separate mixtures?
Filtration, Chromatography, Distillation and Evaporation
What is filtration?
Filtration is a method to separate a mixture of an undissolved solid and a liquid.
1. Filter paper has extremely small holes in it
2.Particles in a liquid or solution are so tiny that they can fit through the holes
3.Larger particles of the solid are too big to fit through the holes and are held back by the paper
What is chromotography?
Chromatography is used to separate mixtures that are soluble in the same solvent.
1. A mixture like ink is placed on piece of paper, which is placed in a solvent
2. As the solvent moves up the paper it separates all the different constituents (parts) of the ink, producing a chromatogram
What is distillation?
A method that separates a solute and a solvent while keeping the solvent.
1. The solution is boiled so the solvent turns in to a gas
2. The gas is then cooled down in a condenser, where it turns back in to a liquid and can be collected
What is evaporation?
A method to separate a solute and a solvent, keeping the solute.
1. The solution is heated then left in an evaporating basin until all the solvent evaporates
2. The solute is left behind as a solid
