1. Ions in Solution

2. Electrolysis During electrolysis ions move towards the electrodes. At the anode (+) Negatively charged ions are oxidised and lose electrons. At the cathode (-)positively charged ions are reduced and gain electrons. Electrolysis involves splitting up a substance with electricity. Ionic substances can only be electrolysed when molten or in solution, because then the ions are free to move. Remember: Oil Rig O xidise R educe I s L ose G ain

3. Electrolysis Continued During electrolysis the least reactive element is produced because it is the most stable as an atom. For instance if you were doing electrolysis of brine Chlorine would be produced at the Anode because it is the least reactive negatively charged ion. Also at the Cathode Hydrogen would be produced instead of sodium because it is less reactive it.

4. The pH Scale 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Strong AcidStrong Alkali H+ ions make solutions acidic OH- (hydroxide Ion) makes solutions alkaline/basic.

5. Neutralization Acid + Metal > Salt +Hydrogen Sulphuric Acid + Potassium > Potassium Sulphate + Hydrogen Acid + Base > Salt +Water Sulphuric Acid + Potassium Oxide > Potassium Sulphate + Water Acid + Alkali > Salt + Water Sulphuric Acid + Potassium Hydroxide > Potassium Sulphate +Water Acid + Carbonate > Salt + Water + Carbon Dioxide Sulphuric Acid + Potassium Carbonate > Potassium Sulphate +Water + Carbon Dioxide

6. Preparation of Insoluble Salts Insoluble Salts can be produced by precipitation reactions, this is where 2 soluble salts are mixed together. It is called a precipitation reaction because the salt is formed as a solid. This reaction is mainly used for removing heavy metal ions from drinking water. E.g. Lead Nitrate + Sodium Chloride > Lead Chloride + Sodium Nitrate Pb(NO3)2 (aq) + 2NaCl(aq) > PbCl2 (s) + 2NaNO3 (aq)

7. Questions 1. Electrolysis cannot occur in solids why is this? 2. Electrolysis is a REDOX reaction what does this mean? 3. During the reaction of a acid and a base, what produces are produced? 4. During the reaction of an acid and a carbonate what is produced? 5. Where does the name of a salt come from? 6. We can make insoluble salts by reacting 2 soluble salts. What is this type of reaction known as? 7. If we reacted Lead Nitrate + Sodium Chloride Pb(NO3)2 (aq) + 2NaCl (aq) What would be the products give their mane and formula 8. What is one of the main uses for this type of reaction? 9. What ion is responsible for making an acid acidic? 10. What ion is responsible for making an alkali alkaline?

8. Answers Because the ions aren't free to move. That Reduction and Oxidisation are happening all the time. A Salt and Water A Salt, Water and Carbon Dioxide The First part comes from the acid that reacted, and the second part comes from the metal. E.g. Sulphuric Acid + Potassium > Potassium Sulphate Precipitation reaction. Lead Chloride + Sodium Nitrate PbCl2 (s) + 2NaNO3 (aq) To purify drinking water by removing heavy ions H+ OH-