1. Topic 9 ReactionsofAcids

2. Neutralisation Neutralisation is the reaction of acids with neutralisers. A neutraliser is a substance which neutralises an acid and so the pH of the acid rises towards 7. We know that acids contain H + ions and water contains few ions.

3. When an acid is neutralised the number of H + ions decreases. In a neutralisation reaction, the pH of an alkali decreases towards 7 and the concentration of OH - ions decreases.

4. Bases are neutralisers. There are 4 types of BASE: Metals, Metal oxides, Metal hydroxides (soluble metal hydroxides are – alkalis) and Metal Carbonates. Ammonia is also an example of a base.  During a neutralisation reaction, water and salt are always formed.

5. Neutralisation in everyday life 1.Adding lime (an alkali) to soil to reduce acidity. 2.Adding lime to lakes to reduce the effect of acid rain. 3.Taking indigestion tablets to treat acid indigestion. 4.Using toothpaste to cancel mouth acidity. 5.Acid rain damaging building and carbonate rocks. 6.Acid rain damaging metal items (cars).

6. Neutralisation in the lab – Reactions of Acids with Neutralisers Acid + Alkali  Salt + Water Acid + Metal Oxide  Salt + Water Acid + Metal Carbonate  Salt + Water + Carbon dioxide Acid + Metal  Salt + Hydrogen