1.3: Separating Mixtures Flashcards
What is a mixture?
A mixture is made up of two or more substances (elements or compounds) that are not chemically combined together.
How can mixtures be separated?
Mixtures can be separated by physical means, such as filtration, crystallisation, and simple distillation.
What is the difference between compounds and mixtures?
Compounds have a fixed composition, while mixtures have no fixed composition.
What is filtration?
Filtration is a technique used to separate substances that are insoluble in a particular solvent from those that are soluble.
How is crystallisation used to obtain pure salt?
Crystallisation involves evaporating water from a salt solution to obtain pure sodium chloride crystals.
What is the process of distillation?
Distillation is a method used to separate a solvent from a solution by heating it to evaporate the solvent and then condensing the vapour back into a liquid.
What happens during the crystallisation process?
Heating should be stopped when small crystals first appear, and the rest of the water is left to evaporate at room temperature.
Why is a water bath used in crystallisation?
A water bath is used for gentler heating compared to direct heating, which helps prevent overheating and ensures better crystallisation.
What is the role of a condenser in distillation?
The condenser cools and condenses the hot vapour back into a liquid for collection.
How can you separate sulfur powder and sodium nitrate?
You can separate them by using xylene to dissolve sulfur and then filtering, followed by dissolving sodium nitrate in water and filtering again.
