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- 1The word pure is used in chemistry in a different way from its everyday meaning. For example, shops sell cartons labelled as 'pure' orange juice. The label means that the contents are just orange juice, with no other substances added. However, the juice is not pure in the chemical sense, because it contains different substances mixed together. In chemistry: ⦁ a pure substance consists only of one element or one compound ⦁ a mixture consists of two or more different substances, not chemically joined togetherFormulation chemistry is the branch of manufacturing that addresses substances that do not react with each other, but have desirable properties as a mixture. These products include paints, varnishes, cosmetics, petroleum products, inks, adhesives, detergents, pesticides, and a broad range of household products.
- 2One use for chromatography is to separate out the mixture of colouring agents in food. To identify which agents are present, run samples of known mixtures alongside the unknown mixtures and compare where the spots end up. You can calculate the Rf value for each chemical- An Rf value is the ratio between the distance travelled by the dissolved substance and the distance travelled by the solvent. Rf = distance travelled by the substance / distance travelled by solventA lighted wooden splint makes a popping sound in a test tube of hydrogen. A glowing wooden splint relights in a test tube of oxygen. (calcium hydroxide solution). Carbon dioxide turns lime-water cloudy white.
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- Flashcards on Untitled, created by person all on 08/04/2018.
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- person all · Apr 2018
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- Oct 14, 2018
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