1. Acids and Alkalis LO: Describe what happens when acids are mixed with water (D) Explain what is making a solution acid or alkali (C) Investigate acids and alkalis and the effect on pH (B) Make conclusions about acids and alkalis based on the work you have done (A/A*) Starter Write down as many substances as you can that are…. ACID ALKALI NEUTRAL

2. State symbols (g)solid (l)aqueous (s)liquid (aq)gas

3. Acids Acids dissolve in water and make H + ions. e.g. HCl (g)  H + (aq) + Cl - (aq) The pH of an ACID is ___________

4. Bases These are substances that can neutralise acids. When they dissolve in water we call them ALKALI E.g. Iron oxide Sodium Hydroxide When bases dissolve they increase the amount of OH - in the water NaOH (s)  Na + (aq) + OH - (aq) The pH of an ALKALI is ___________

5. ACID H + ALKALI OH - NEUTRAL H + and OH -

6. Measuring acidity and alkalinity

7. The pH scale is used pH 7 = pH less than 7 = pH more than 7 = Indicators will change colour in these. The colour change depends on the indicator (THE COLOURS FOR UNIVERSAL INDICATOR DON’T ALWAYS WORK)

8. Practical Use the dimple tiles to find out what the pH of different substances are. Record your results.