1. Topic 9 ReactionsofAcids

2. Acids and Metals Think of the effect of acid rain on iron bridges and cars. When the acid rain falls on them a chemical reaction occurs. (Neutralisation reaction) Acids react with metals to produce a salt and hydrogen gas. (This does not happen with all metals.)

3. Metal + Acid  Salt + Hydrogen Iron + Hydrochloric acid  Iron(II)Chloride + Hydrogen Fe+HCl  FeCl 2 + H 2

4. Metal + Acid  Salt +Hydrogen (MAZIT metals see pg 7 of d.b.) Mg (s) +H 2 SO 4(aq)  MgSO4 (aq) + H 2(g) This reaction involves both oxidation and reduction and it is known as a redox reaction. The sulphate ions do not change in the reaction and so are called spectator ions. Mg (s) + H 2+ SO 4 2- (aq)  Mg 2 SO 4 2- (aq) +H 2(g) NB: The H + ions form H 2 molecules.

5. Sulphuric acid contains hydrogen ions (H + ) and sulphate ions (SO 4 2- ). Magnesium is reacting with hydrogen ions from the acid. Magnesium atoms are losing electrons to the hydrogen ions. This means that the magnesium atoms are being oxidised and the hydrogen ions are being reduced. OilReduction IsIsIsIs LossGain

6. ElementsReaction Potassium, Sodium, Calcium and Magnesium React violently Zinc, Iron and LeadReact slowly Copper, Silver and GoldNo Reaction

7. Experiment Aim: To investigate which metals react with acid. Method: Zn + acid Cu + acid Mg + acid

8. Results: Record the time taken for each metal to fully react. Conclusion: Metals ABOVE hydrogen in the electrochemical series (E.C.) react with acids. Metals BELOW hydrogen do not react with acids! (See pg 7 of d.b)