Chemistry - 1 Atomic Structure - 1.3 Separating Mixtures

Mixture

A combination of two or more substances that are not chemically combined

Ratios (c vs m)

- Compounds have a fixed composition
- Mixtures have no fixed composition

Separation (c vs m)

- Compounds must be separated by chemical reactions
- Mixtures can be separated by physical means, using the properties of each separate substance

Chemical bonds (c vs m)

- Compounds contain different elements chemically bonded
- There are no chemical bonds between atoms of a different substance in a mixture

Filtration

A process used to separate an insoluble substance from a solvent - usually with filter paper and a funnel

Filtering sand [3]

- The sandy water is poured through filter paper
- The sand collected on the paper is rinsed to remove any remaining soluble solvents
- The sand is dried in a warm oven to evaporate off the water

Crystallisation

The formation of crystals by evaporating a solvent from a saturated solution

Crystallisation process [3]

- Heat an evaporating dish containing the saturated solution (either in a water bath or directly on the gauze and tripod)
- Stop heating at the point of crystallisation
- Leave the rest of the solvent to evaporate at room temp

Filtrate

liquid that has passed through a filter

solvent

A liquid substance capable of dissolving other substances

solute

A substance that is dissolved in a solution.

Distillation

A process that separates the substances in a solution based on their boiling points

Simple distillation

- Solution is heated over Bunsen burner
- A thermometer is placed so that we can record the gas's temperature
- the gas enters a condenser where it is cooled and again becomes liquid
- The liquid enters another glass

Condenser

A tube with an outer jacket that has water flowing through it, acting as a coolant to condense the vapours inside