Karteikarten
module 7
Karten in diesem Stapel (26)
- 1types of mixuresSome substances are pure, however most substances used daily are mixtures, the air we breath, water from our taps, milk etc.
Mixtures can be separated
The different types of mixtures are:
Solutions, suspensions, colloids and solids. - 2solutionsSubstances, which dissolve in another are called
soluble.
When a substance does not dissolve it is said to be insoluble.
When things dissolve it the resulting mixture is called a solution.
The substance which dissolves is known as the
solute
The substance that dissolves the other is called the solvent. - 3types of solutions• Solid dissolved in a solution e.g. sugar dissolved in water, grease dissolved in petrol
• Liquid dissolved in another liquid e.g. Liquid detergent dissolved in water, vodka in tonic water
• Gas dissolved in a liquid e.g. oxygen gas dissolved in water
• Gas dissolved in another gas e.g. oxygen (O2), carbon dioxide (CO2) and water vapour dissolved in the other gases in air (N2 etc.) - 4more solutions• If solutions are transparent (light passes through) it is described as clear
• Solutions can be coloured or colourless
• How would you describe water?
clear and colourless
• Blue copper sulphate dissolved in water?
clear and blue - 5concentrations• Concentration is a measure of amount of solute dissolved in a known amount of solvent.
• Large amount = concentrated
• Small amount = dilute
• When a substance will no longer dissolve in a solvent, the solution is said to be saturated
• E.g. if you place spoonfuls of salt into a glass of water until the salt stops dissolving - 6Dissolve 5g of sugar in 10L of waterDivide = mass 5/Volume 10=0.5g/L
- 7suspensions• A suspension is when one substance does not dissolve, and separates out when the mixture is allowed to stand.
• The particles in suspensions are larger than those found in solutions. Components of a suspension can be evenly distributed by a mechanical means, like by shaking the contents, but the components will settle out.
• When a suspension part is mixed and spread out, it is called a dispersion. - 8types of suspensionsSolid suspended in a liquid e.g. sand in water, flour in water.
• Solid suspended in a gas e.g. sand carried by the wind, dust in the air
• Liquids suspended in another liquid e.g.
many medicines are suspensions of liquids within another liquid, oil paints etc. - 9colloids• Particles intermediate in size between those found in solutions and suspensions can be mixed such that they remain evenly distributed without settling out. These particles range in size from 10-8 to 10-6 m in size and are termed colloidal particles or colloids. The mixture they form is called a colloidal dispersion. A colloidal dispersion consists of colloids in a dispersing medium.
- 10more colloids• Colloids can be distinguished from solutions using the Tyndall effect.
• A beam of light passing through a true solution, such as air, is not visible.
• Light passing through a colloidal dispersion, such as smoky or foggy air, will be reflected by the larger particles and the light beam will be visible. - 11more types of colloids• A common type of colloids is called an emulsion. An emulsion is a mixture of a liquid in a liquid where one liquid will not dissolve another
• E.g. Mayonnaise (oil in water)• Foam- a gas dispersed in a liquid of a solid e.g. shaving foam, and foam found in sofas
• Gel- a liquid dispersed in a solid e.g. jelly
• Sol – a solid dispersed in a liquid e.g. blood - 12separating insoluble substance• Gravity separation
• Decanting
• Sieving
• Filtration
• Magnetic separation
• Centrifuging - 13gravity seperationUses gravity to separate heavier substances from a suspension. Heavier particles sink to the bottom e.g. panning for gold
• Decantation is type of gravity separation that allows suspensions of solids of liquids naturally. The top layer can be poured off gently. - 14sieving• Using an instrument with a meshed or perforated bottom, used for separating coarse from fine parts of loose matter, for straining liquids, etc., especially one with a circular frame and fine meshes or perforations.
- 15more siveingFiltration is used widely to separate
• Solids from gases
• Solids from liquids
• Liquids from gases
• Liquids from other liquids It uses a filter, a barrier
with very small holes - 16magnetic seperationIron, nickel and cobalt are the only three pure metals that always attracted to a magnet.
• Alloys are metals mixed with other metals such as carbon. Steel is an alloy of iron and carbon and is magnetic.
• Magnetic separation is widely used in the mining industry, scrap metal and recycling.
• The material is passed through a large magnetic drum, the magnetic materials are attracted to the drum while the non-magnetic material is allowed to flow through. - 17centrifugeA is an apparatus that rotates at high speed and by centrifugal force separates substances of different densities e.g. blood samples are centrifuged to separate red and white blood cells and liquid plasma.
- 18seprating soluable substances• Chromatography*
• Evaporation
• Distillation
• Adsorption
• Purifying water - 19• Chromatographyis a process that can separate a mixture by making it move through another substance like a paper strip or in chemical laboratories thin layer chromatography plates (tlc)
• Chromatography works because all the chemicals in the mixture are attracted to the solid material by different amounts. - 20more Chromatography• is used in industry e.g. to find out the pollutants in oil and gas, the different chemicals in pharmaceutical drugs,
- 21• Evaporationis a process that uses heat to make a liquid solvent change state to a gas, leaving the solute behind.
• Natural process that dries up pools of puddles or dries our clothes on the washing line
• Used in a chemical laboratory to separate a solvent from a solute- disadvantage the solvent is lost to the atmosphere.
• If the solute forms crystals it is also known as crystallisation. - 22• Distillationis a process that uses evaporation and condensation to separate solids from liquids or liquids from liquids, enabling the recovery of both.
- 23more distillation• As well as separating solutions in laboratories distillation is used in:
• Producing alcoholic drinks such as vodka and whiskey
• Separating crude oil into petrol, diesel, lubrication oils and other components
• Removing impurities from drinking waters
• Separating oxygen, nitrogen and argon from air for industrial use - 24adsorption• Adsorption is a method of separation where particles of liquid, solid or gas stick to the outside of a solid.
- 25purifying water• Water sources
• Ground water
• Desalination
• Water treatment
• Sewage and recycled water • Protecting our water - 26—
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- Karteikarten am module 7, erstellt von brittany willowgem am 30/05/2019.
- Erstellt von
- brittany willowgem · Mai 2019
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- 30 Mai 2019
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