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C3 Electrolysis
Edexcel C3 Electrolysis
| Question | Answer |
|---|---|
| A gas which forms at cathode | Hydrogen |
| Which ions are attracted to the cathode | Metals ions (or cations) |
| The positive electrode | Anode |
| Which ions are attracted to the anode | Non-metals ions (or anions) |
| The negative electrode | Cathode |
| How the metal ions become atoms at the cathode | Gain electrons |
| A positively charged ion | Cation |
| How the non-metal ions become atoms at the cathode | Lose electrons |
| A negatively charged particle | Anion |
| What state compounds must be in order to separate by electrolysis | Molten |
| What is a charged particle | Ion |
| What is oxidation? | Loss of electrons |
| What is reduction? | Gain of electrons |
| Describe how to make the ions in an ionic compounds mobile | Melt the compound or Dissolve it in water |
| The charge formed on metals ions | Positive |
| Is this a possible reaction at an anode? Mg+2 + 2e- Mg | No, at the anode non-metals ions are losing electrons, non-metal ions are oxidised |
| The charge normally formed on non-metal ions | Negative |
| A possible reaction at a cathode? Mg+2 + 2e- Mg | Yes, at the cathode, metal ions gain electrons, metal ions are reduced |
| Is this an oxidation or a reduction? 2Cl- Cl2+2e- | Oxidation, because electrons are lost |
| Is this an oxidation or a reduction? Mg+2 + 2e- Mg | Reduction, because electrons are gained |
| What will be collected at the anode during the electrolysis of molten copper chloride (inert electrodes)? | Chlorine |
| What will be collected at the anode during the electrolysis of copper chloride solution (inert electrodes)? | Chlorine |
| What will be collected at the cathode during the electrolysis of molten copper chloride (inert electrodes)? | Copper |
| What will be collected at the cathode during the electrolysis of copper chloride solution (inert electrodes)? | Hydrogen |
| What will be collected at the anode during the electrolysis of copper sulfate solution (inert electrodes)? | Oxygen |
| What will be collected at the cathode during the electrolysis of copper sulfate solution (inert electrodes)? | Copper |
| What will be collected at the anode during the electrolysis of sodium sulfate solution (inert electrodes)? | Oxygen |
| What will be collected at the cathode during the electrolysis of sodium sulfate solution (inert electrodes)? | Hydrogen |
| Describe and Explain the reaction taking place at the cathode during electrolysis, in terms of electron transfer | At the Cathode, the metal ion gains electrons: it is a reduction [Have you used keywords? Have you said HOW MANY electrons?] |
| Describe and Explain the reaction taking place at the anode during electrolysis with INERT electrode, in terms of electron transfer | At the Anode, the non-metal ion lose electrons: it is an oxidation [Have you used keywords? Have you said HOW MANY electrons?] |
| Describe and Explain the reaction taking place at the anode during electrolysis with ACTIVE electrode, in terms of electron transfer | At the Anode, the Copper metal ATOMS lose electrons to form IONS; the copper ion dissolve in solution: it is an oxidation [Have you used keywords? Have you said HOW MANY electrons?] |
| Why does an ionic compound only conduct electricity when molten? | ions are free to move |
| What are the electrodes made of in the purification of copper? | Copper metal |
| What are the ions in molten Copper Chloride? | Copper ions and Chloride ions |
| What are the ions in Copper Chloride solutions? | Copper ions, Hydrogen ions, Hydroxide ions and Chloride ions |