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• Super Challenge:

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  Challenge:

Key Questions:

1. When is an ionic compound able to conduct electricity?
   • When an ionic compound is melted or dissolved in water, the ions are free to move about within the liquid or solution. These liquids and solutions are able to conduct electricity and are called electrolytes.
2. (HT) What is the balanced half equation for H ? e??? H2
   • T(HT)he balanced half equation is: 2H ? 2e??? H2
3. What happens at each of the electrodes in electrolysis when an electric current is passed through the electroytes?
   • Passing an electric current through electrolytes causes the ions to move to the electrodes. Positively charged ions move to the negative electrode (the cathode), and negatively charged ions move to the positive electrode (the anode). Ions are discharged at the electrodes producing elements. This process is called electrolysis.
4. (HT) What happens at the anode and cathode electrodes in the electrolysis of aqueous sodium chloride? (use half equations to help explain)
   • (HT) At the cathode sodium is formed: 2Na 2e- --> 2Na At the anode chlorine gas is formed: 2Cl- -->Cl2 2e-
5. Which electrode as the metals and non metals products found during electrolysis?
   • During electrolysis the metal product is found at the cathode as this cathode is negatively charged. The non metal product is found at the anode, this this electrode is positively charged.
6. What would the products be for the electrolysis of the following ionic compounds: 1. NaCl 2. PbBr2 3. NaOH 4. Al2O3
   • The products of electrolysis would be: 1. H2 (g) Cl2 (g) NaOH (aq) 2. Pb (s) Br2 (g) 3. H2 (g) O2 (g) Na (aq) 4. Al (s) O2 (g)
7. (HT) What would the half equations be for the electrolysis of NaCl?
   • (HT) anode: 2Cl– → Cl2 2e- (oxidation) cathode: 2H 2e– → H2 (reduction). NaOH solution is also produced.
8. What happens at the cathode during electrolysis? Is this an oxidation or reduction reaction?
   • During electrolysis, at the cathode (negative electrode), positively charged ions gain electrons and so the reactions are reductions.
9. What happens at the anode during electrolysis? Is this an oxidation or reduction reaction?
   • At the anode (positive electrode), negatively charged ions lose electrons and so the reactions are oxidation reactions.
10. What would the half equations be during the electrolysis of PbBr2?
    • anode: 2Br– → Br2 2e- (oxidation) cathode: Pb2 2e– → Pb (reduction).