Section 1 - Types of Reactions Section 2-Testing for Gases Key Words Phrase Definition Phrase Definition (highlighted) A reaction where energy is given out to the To test for hydrogen use a lit splint, if it surroundings. The surroundings then have more 2a Hydrogen test makes a ‘squeaky pop’ sound then 1a Exothermic energy than it started with. This shows as an hydrogen is present. increase in temperature. To test for oxygen use a glowing splint, 2b Oxygen test LINK A reaction where energy is taken in. The reaction if it reignites oxygen is present. requires more energy than the reactants so it 1b Endothermic Bubble the gas through limewater and Extended absorbs energy from the surroundings. This shows 2c Carbon dioxide test if it turns cloudy then carbon dioxide is reading as a temperature decrease present. The process of burning a fuel in the presence of 1c Combustion oxygen. 2d Limewater Calcium hydroxide solution. It turns Thermal Type of reaction in which a compound breaks down milky in the presence of carbon dioxide LINK 1d decomposition to form two or more substances when it is heated. Exam 1f- products Substances present at the start of a chemical 1e- reactants questions 1e Reactants reaction. C3- Chemical 1f Products A substance formed in a chemical reaction. Reactions
LINK When a substance bonds with oxygen it is 1g Oxidation oxidised. Video e.g magnesium + oxygen → magnesium oxide. links A compound made of only hydrogen and carbon. 1h Hydrocarbon These are common as fuels.
When a more reactive element displaces a less 1i Displacement reactive element. LINK 2c- Carbon dioxide test 2a- Hydrogen test Revision 2b- Oxygen test techniques
LINK Key Section 3-Acids and Alkalis Section 4- Neutralisation Words (highlighted) Phrase Definition Phrase Definition Scale of acidity or alkalinity. A pH Neutralisation When you combine and acid and alkali to 4a 3a pH scale value below 7 is acidic, a pH value make a neutral substance. above 7 is alkaline. The salt made depends on the acid. The LINK Corrosive substance which has a salt begins with the metal and ends with pH lower than 7. Such as: sulfuric the acid + suffix. 3b Acid Extended acid, hydrochloric acid or nitric e.g reading acid. Naming salts Hydrochloric acid makes a 4b ______Chloride A substance that reacts with an Sulfuric acid makes a 3c Alkali acid to neutralise it and produce a ______Sulfide salt. Has a pH above 7. Nitric acid makes a LINK A chemical solution that produces C3-Chemical ______Nitrate Universal 3d many different colour changes to Exam indicator Reactions show different pH levels. 4c Acid + Metal acid + metal salt + hydrogen questions
A paper that changes colour to Acid + Metal 4d acid + metal oxide salt + water 3e Litmus paper determine if a solution is acid or Oxide alkali using the pH scale. Acid + 4e acid + metal hydroxide salt + water LINK Able to damage metal, stonework, Hydroxide 3f Corrosive clothes and skin. Strong acids and Acid + acid + metal carbonate salt + water + Video alkalis are corrosive. 4f Carbonate carbon dioxide links A chemical that can cause 3g Irritant inflammation and irritation. 3a- Neutralisation
3a- pH scale LINK
Revision techniques
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