This Science quiz will test you on acid reactions. Acids are chemicals which readily release hydrogen ions into solution. This property makes them react in predictable ways with other substances, in particular metals and bases.
At GCSE level you need to know what will be made when hydrochloric or sulfuric acid react with a metal, and when hydrochloric, sulfuric or nitric acid are neutralised by a base. A base is any substance that will neutralise an acid, and an alkali is simply a soluble base.
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You can find more about this topic by visiting BBC Bitesize - Acids, alkalis and salts - AQA
Iron chloride is a salt. A salt is a chemical made when the hydrogen in an acid is replaced by a metal. The formula for hydrochloric acid is HCl. If you replace the hydrogen with iron you are left with a compound made from iron and chlorine – iron chloride!
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The clue here is in the name CARBONate. Carbonates are bases, so a neutralisation reaction will occur, making a salt and water, but the carbon from the carbonate has to end up somewhere, so it turns into CO2 gas. These reactions always fizz
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Remember that a salt is made when the hydrogen in an acid is replaced by a metal. So acid + metal reactions are really just a special case of a displacement reaction. The metal pushes the hydrogen out of solution, so these reactions fizz
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This is a neutralisation reaction between an acid and a base, so the products will be a salt and water. Nitric acid has the formula HNO3, so the salt will contain the NO3- ion. Since oxygen as well as nitrogen is present in this product, the name will end –ate not –ide
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Hydrogen is highly flammable, so we test for it by setting fire to it. The distinctive pop sound of the explosion indicates the presence of hydrogen
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Carbon dioxide will extinguish a flame, but so will other gases, so testing for flammability is not a specific test for CO2. When it is bubbled through limewater a precipitate of calcium carbonate (chalk) is made which turns the clear solution cloudy or milky
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I think the best way of remembering this is by using a poem:
Johnny was a scientist, Johnny is no more For what he thought was H2O was H2SO4 |
Chlorides, sulfates and nitrates are all salts, made by replacing the hydrogen in, respectively hydrochloric acid, sulfuric acid and nitric acid. The oxygen in magnesium oxide will join up with the hydrogen from the acid to make water; oxides are bases as are hydroxides and carbonates
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Copper sulfate needs to be made by a neutralisation reaction. Copper metal is too unreactive to react with an acid directly, so either copper oxide or copper carbonate would have to be used
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Metal atoms always lose electrons when they react, becoming positive ions. Magnesium is in group 2 of the periodic table, so it has two electrons in its outer shell and therefore will lose both of them to become a 2+ ion. We say that the magnesium has been oxidised, because oxidation is loss of electrons
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