science education teaching

Compounds and Reactions Word Equations Year 10 Word Equations Equations are used to show how chemical reactions occur. An equation has products, reactants, and an arrow. Nothing new is created and nothing disappears in a reaction, elements just get moved around. • • The reactants are on the left-hand side of the arrow and react together. The products are on the right-hand side of the arrow and are formed from the reactants. Examples Acid Metal Acid Magnesium Hydrogen Water Copper Carbonate Hydrochloric Acid + + Hydrochloric Acid Sodium Hydroxide + Alkali + Acid + Carbonate + Oxygen + Oxygen -> -> -> -> -> -> -> -> Salt + Water Salt + Hydrogen Salt + Carbon Dioxide Magnesium Oxide Water Hydrogen + Oxygen + Water + Water + Water + Water Copper Chloride + Carbon Dioxide Sodium Chloride Common Reactions There are some chemical reactions which are very common. It is important to be able to recognise and predict these reactions. 1 2 3 4 5 Acid and Alkali Acid and Metal Acid and Carbonate Decomposition Combustion Produces water Produces salt, hydrogen, and water Produces salt, carbon dioxide, and water Breakdown of a compound into elements Means reacting with oxygen; or burning R Laugesen 16/07/2008 Compounds and Reactions Word Equations Year 10 Questions 1. Highlight the example reactions. Reactants with one colour and the products another colour. 2. Write the reaction-type number next to each example reaction. 3. How would you test an unknown reaction for Hydrogen? 4. How would you test an unknown reaction for Carbon Dioxide? 5. If an unknown reaction produces water then what type of reaction could it be? 6. If the same reaction also produces carbon dioxide then what type of reaction could it be? 7. When you burn wood on a fire what type of reaction is occurring? 8. Can you see a rule for determining what reactant elements are in the salt products? 9. Write the reaction-type number next to these reactions. Then try to determine the products. Sodium Zinc Magnesium + Oxygen + Sulfuric Acid + Sulfuric Acid -> -> -> -> -> + + + + + Water + Water + Water Hydrogen Chloride Copper Carbonate + Sulfuric Acid R Laugesen 16/07/2008 Compounds and Reactions Word Equations Year 10 R Laugesen 16/07/2008