What colour does a strong acid turn universal indicator? red A substance turns universal indicator green what do we describe this solution as? What could the solution be? Neutral water A substance turns universal indicator a dark purple/blue, what is it? alkali

Success… In order to be successful in this lesson you must be able to: Learning Objectives: In order to be successful in this lesson you must be able to: Explain the reaction between an acid and a base and give everyday examples of neutralisation reactions Success…

Task 2: What happens when we add acid to a base? Safety! Wear goggles STAND UP Tie hair up Be sensible Task 2: What happens when we add acid to a base? Follow the instructions on the sheet to carry out the practical The science bit… Record what happened in your book and answer the questions in full sentences ACID + METAL HYDROXIDE  SALT + WATER. Use this equation to write a word equation for the reaction you have just done

A neutralisation reaction is where an acid reacts with a base to produce a neutral solution of a salt and water. sodium hydroxide pH 14 neutralisation sodium chloride pH 7 hydrochloric acid pH 1 1 2 14 13 12 11 10 9 8 7 6 5 4 3 Increasingly acid Increasingly alkali

Acid + alkali  salt + water hydrochloric acid sodium hydroxide sodium chloride +  + water HCl + NaOH  NaCl + H2O nitric acid potassium hydroxide potassium nitrate +  + water + KOH  HNO3 KNO3 + H2O sodium hydroxide sodium sulphate sulphuric acid +  + water + 2NaOH  H2SO4 Na2SO4 + H2O

Neutralisation Wasp stings are treated with vinegar Bee stings are treated with bicarbonate of soda What does this tell us about the pH of the bee and wasp stings?

Importance of neutralisation An ant has stung Roxanne. Alexander tells her that ant sting is formic acid. How could Roxanne treat her sting? Explain how your treatment would work

Acid rain causes lakes to become acidic killing fish and damaging the surrounding environment We can fix this problem by neutralising the acid in the lakes We an alkali to do this Acid + Alkali → salt + water

Antacids Antacids can be taken to relieve the pain of acid reflux. Antacids work by neutralising the acid in your stomach. They do this because the chemicals in antacids are bases (alkalis) which are the opposite of acids. When antacids work on stomach acid they can produce gas which may cause burping.

1. What acid does your stomach produce? (name and symbol) 2. Give two reasons why your stomach produces Hydrochloric acid. 3. What is indigestion? 4. What is heartburn? 5. What do antacids do? Give two examples of antacids. 6. What is the general word for a neutralisation reaction?

1. What acid does your stomach produce? (name and symbol) Hydrochloric acid 2. Give two reasons why your stomach produces Hydrochloric acid. Kill bacteria and to break down food. 3. What is indigestion? When the stomach produces too much acid. 4. What is heartburn? When the acid escapes from the top of the stomach and causes pain in the tube leading to the mouth. 5. What do antacids do? Give two examples of antacids. They neutralise excess acid. E.g. Calcium carbonate, magnesium carbonate. 6. What is the general word for a neutralisation reaction? Acid +base -> salt + water

Neutralisation: Writing equations Chemicals you started with (REACTANTS) Chemicals end up with (PRODUCTS) Acid + Alkali Salt + Water Sodium + Hydrochloric Hydroxide acid Sodium + Water chloride Copper + Sulfuric oxide acid Copper + Water sulfate

Success… In order to be successful in this lesson you must be able to: Learning Objectives: In order to be successful in this lesson you must be able to: Explain the reaction between an acid and a base and give everyday examples of neutralisation reactions Success…