Do now! Can you spell the following words correctly in the back of your book? Nuetralisasion, indicater, litmas, alkcali, burete.

Acids and alkalis What have you learnt?

Acid tastes

Acid comes from the latin word acer, which means sharp. Acids are sharp tasting! (“Tangy”)

Indicators Indicators are chemicals (coloured dyes) which change colour in acids and alkalis.

Litmus Turns red in acid Turns blue in alkali

Litmus Turns red in acid Turns blue in alkali Litmus can tell us if something is an acid or an alkali, but it cannot tell us how strong the acid or alkali is

Other indicators Red cabbage and beetroot make excellent indicators

The pH scale The strength of an acid is measured on the pH scale pH stands for the “potential of hydrogen”

Universal Indicator To measure pH, we need an indicator that has a different colour for each value of pH Universal Indicator

It comes in the form of a paper

Universal Indicator It also comes in the form of a liquid

Neutralisation

What happens when we add an acid to an alkali?

Neutralisation Acid + alkalisalt + water Both neutral

Examples of neutralisation

Chemical Hazard Symbols Corrosive – dissolves metals, stone and skin Irritant – harms eyes and skin Flammable – burns easily Toxic – poisonous

Summary sheet Can you stick the summary sheet into your books?

Summary exercise

Read pages 64 and 65 Abigail Tom

Read pages 64 and 65 Abigail Tom Can you now write 6 multiple choice questions to go with these pages

Multiple choice questions What is a burette used for?

Multiple choice questions What is a burette used for? A. to add measured amounts of a liquid

Multiple choice questions What is a burette used for? A.to add measured amounts of a liquid B.to stir reactants together

Multiple choice questions What is a burette used for? A.to add measured amounts of a liquid B.to stir reactants together C.to grind solids into a powder

Multiple choice questions What is a burette used for? A.to add measured amounts of a liquid B.to stir reactants together C.to grind solids into a powder D.to make french toast

Read pages 64 and 65 Abigail Tom Can you now write 6 multiple choice questions to go with these pages

TEST We will be having an acids and alkalis TEST on Monday 17 th December