1. 6.3 Electrolysing brine Brine is salty water. It’s chemical name is sodium chloride, NaCl aq. Both elements are useful in thousands of products. 04 May 2015

2. 6.3 Electrolysing brine Brine can be electrolysed into –Sodium Hydroxide (NaOH) –Chlorine (Cl) –Hydrogen (H 2 ). Some of the uses of the products of the electrolysis of brine are; –Soap (NaOH) –PVC (Cl) –Bleach (NaOH + Cl) –Margerine (H 2 ) 04 May 2015

3. Diaphragm cell What type of ion does chlorine form? What type of ion for hydrogen? Sodium is more reactive than Hydrogen so does not gather at the cathode.

4. Practical 1.Set up the apparatus as shown. 2.Write down your observations as shown below. 6V Beaker with saturated brine and Universal Indicator Diagram Wear Eye Protection. Caution: Sodium Hydroxide Chlorine Method ElectrodeObservations Anode (+) Cathode (-) Results

5. Questions 1.Name the gas given off at each electrode. 2.What are the four ions present in the brine? 3.Which ions remain in the solution? 4.What compound would they form?

6. Answers 1.Name the gas given off at each electrode. Anode = Chlorine, Cathode = Hydrogen 2.What are the four ions present in the brine? Sodium +, Chloride -, Oxide 2-, Hydrogen + 3.Which ions remain in the solution? Sodium +, Oxide 2-, Hydrogen + 4.What compound would they form? Sodium Hydroxide (NaOH)

7. Uses of electrolysed brine 1.Margarine 2.PVC 3.Bleach 4.Soap 5.Paper 6.Rayon fibres 7.Detergents 8.Purification of aluminium ore 9.Hydrochloric acid manufacture Brine produces 3 main products. Which products are used for; NaOHH2H2 Cl

8. Uses of electrolysed brine 1.Margarine [hydrogen] 2.PVC [chlorine] 3.Bleach [sodium hydroxide, chlorine] 4.Soap [sodium hydroxide] 5.Paper [chlorine] 6.Rayon fibres [sodium hydroxide] 7.Detergents [sodium hydroxide, chlorine] 8.Purification of aluminium ore [sodium hydroxide] 9.Hydrochloric acid manufacture [chlorine, hydrogen]

9. 6.3 Electrolysing brine Brine can be electrolysed into –Sodium Hydroxide (NaOH) –Chlorine (Cl) –Hydrogen (H 2 ). Some of the uses of the products of the electrolysis of brine are; –Soap (NaOH) –PVC (Cl) –Bleach (NaOH + Cl) –Margerine (H 2 ) 04 May 2015