Presentation on theme: "Starter 1. Explain why molten sodium chloride conducts electricity but solid sodium chloride does not. 2. Explain why although neither lithium chloride."— Presentation transcript:
Starter 1. Explain why molten sodium chloride conducts electricity but solid sodium chloride does not. 2. Explain why although neither lithium chloride (LiCl) nor tetrachloromethane (CCl 4 ) conducts electricity when solid, lithium chloride conducts when liquid. 3. Copy and complete the following table: SubstanceSolid stateLiquid state Phosphorous CopperConducts Calcium oxide
Aim: To investigate the electrolysis of an ionic solution
Method: 6v DC Observe what happens at each electrode. Copper chloride solution Negative electrode Positive electrode Aim: To investigate the electrolysis of an ionic solution
Results: SolutionProduct at -ve electrode +ve electrode CuCl 2 Brown solid Copper Bleach smell chlorine (g)
+- Cu 2+ Cl - Cu 2+ Positively charged copper ions are attracted to the negative electrode
+- Cu 2+ Cl - Cu 2+ Negatively charged chloride ions are attracted to the positive electrode
+- Cu Cl Cu Chlorine atoms form at the positive electrode as chlorine gas (Cl 2 ) Copper atoms form at the negative electrode as solid metal
Conclusion: Negative Electrode Copper solid is formed as the positive metal copper ions (Cu 2+ ) are attracted to the negative charge. Positive Electrode Chlorine gas is formed as the negative non-metal ions (Cl - ) are attracted to the positive charge.
ELECTROLYTES: Compounds which conduct electricity when molten or when in solution. ELECTROLYSIS: The process of ‘breaking-up’ an ionic compound when a current of electricity is passed through a molten electrolyte or electrolyte solution.
Why do we use a direct current (D.C.) for electrolysis? A D.C. current is used so that the separate products can be identified at each electrode.