All Resource articles – Page 42
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Melting point determination
The measurement of melting points is a relatively straightforward procedure that is carried out to determine the purity of a compound or to assist with its identification. A pure compound will melt over a relatively narrow temperature range, impurities both lower and widen the temperature range over which a compound ...
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Streamwatch - a UK water analysis science project
The resource provides access to a water analysis kit and instructions on how to use these. Using this resource provides teachers with great potential to engaging students and enable them to see the purpose and benefits of chemical analysis. The resource could be used for project work and is particularly ...
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Drying liquids
There are many instances when it is necessary to remove traces of water from a solution or liquid. One common example is the drying of an organic layer after a solvent extraction. The technique involves adding a suitable solid drying agent to the liquid followed by its removal by gravity ...
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Cooling mixtures
Cooling baths are very useful in chemistry labs to control exotherimc reactions. In this resource we share various recipes for making cooling baths to temperatures below 0°C. There are many instances where you will need cooling as part of the procedure, for example in recrystallisation, carrying out reactions at low ...
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Distillation
Distillation separates liquids on the basis of them having different boiling points. Video: Distillation video
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Solvent extraction
This technique uses two solvents which are immiscible, for example an organic solvent such as diethyl ether can be used to extract an organic compound from an aqueous solution leaving water soluble impurities behind. A variation of this is acid - base extraction where acidic or basic compounds are extracted ...
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Recrystallisation
Recrystallisation is a means of purifying solids. If carried out correctly the final product will be both of a high yield as well as pure. Video: Recrystallisation video
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Vacuum filtration
When a solid needs to be isolated from a solution it is normally done at a reduced pressure using a Buchner flask and Buchner funnel. Video: Vacuum filtration video
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Standard solution
A standard solution is a a solution of accurately known concentration prepared from a primary standard (a compound which is stable, of high purity, highly soluble in water and of a high molar mass to allow for accurate weighing) that is weighed accurately and made up to a fixed volume. ...
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Soxhlet extraction
When a compound of low solubility needs to be extracted from a solid mixture a Soxhlet extraction can be carried out. The technique places a specialised piece of glassware in-between a flask and a condenser. The refluxing solvent repeatedly washes the solid extracting the desired compound into the flask. ...
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Interactives rock cycle
This tutorial gives students information about types of rocks and how they are formed and change as they progress through the rock cycle. The tutorial contains numerous animations and a quiz to test students which provides feedback.This resource has been developed by Annenberg Learner.
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Space: science ideas webs
A web of suggested ideas for linking science with the topic space. You can learn history and science together with activities for different age groups.
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The Victorians: science ideas webs
A web of suggested ideas for linking science with the topic the Victorians. You can learn history and science together with activities for different age groups.
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The Stone Age: science ideas webs
A web of suggested ideas for linking science with the topic the stone age. You can learn history and science together with activities for different age groups.
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Maya and Aztecs: science ideas webs
A web of suggested ideas for linking science with the topic the Maya and Aztecs. You can learn history and science together with activities for different age groups.
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The Romans: science ideas webs
A web of suggested ideas for linking science with the topic the Romans. You can learn history and science together with activities for different age groups.
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Ancient Egypt: science ideas webs
A web of suggested ideas for linking science with the topic Ancient Egypt. You can learn history and science together with activities for different age groups.
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The Tudors: science ideas webs
A web of suggested ideas for linking science with the topic the Tudors. You can learn history and science together with activities for different age groups.