Electrolysis- In Aqueous solution

• What is the main concept of electrolysis of aqueous solutions?


  It involves the discharge of ions from water and solutes.
• What ions are present in a solution of copper(II) sulfate (CuSO₄)?


  Cu²⁺, SO₄²⁻, H⁺, and OH⁻.
• Why is copper metal produced at the cathode during the electrolysis of copper(II) sulfate?


  Because copper is less reactive than hydrogen.
• What is the half equation for the reduction of copper ions at the cathode?

  $Cu^{2+} +$$2e^{-} \rightarrow Cu$
• What is produced at the anode during the electrolysis of copper(II) sulfate?


  Oxygen and water are produced.
• What is the half equation for the production of oxygen at the anode?


  $4OH^{-} \rightarrow O_{2} +$$2H_{2}O +$$4e^{-}$
• What ions are present in a solution of sodium chloride (NaCl)?


  Na⁺, Cl⁻, OH⁻, and H⁺.
• Why is hydrogen gas produced at the cathode during the electrolysis of sodium chloride?


  Because sodium metal is more reactive than hydrogen.
• What is the half equation for the production of hydrogen gas at the cathode?


  $2H^{+} +$$2e^{-} \rightarrow H_{2}$
• What is produced at the anode during the electrolysis of sodium chloride?


  Chlorine gas is produced.
• What is the half equation for the production of chlorine gas at the anode?


  $2Cl^{-} \rightarrow Cl_{2} +$$2e^{-}$
• What is the importance of balancing electrons in half equations during electrolysis?


  • Ensures conservation of charge
  • Allows for accurate combination of half equations
  • Maintains stoichiometry of the overall reaction
• What is the ionic equation for the electrolysis of aqueous sodium chloride?


  $2H^{+} +$$2Cl^{-} \rightarrow H_{2} +$$Cl_{2}$
• What happens when a halide is not present in the aqueous solution during electrolysis?


  The half equation for the anode changes to produce oxygen instead of halogen.
• What is the half equation for the anode when a halide is absent?


  $4OH^{-} \rightarrow O_{2} +$$2H_{2}O +$$4e^{-}$
• What is produced at the anode and cathode during the electrolysis of copper bromide (CuBr₂)?


  • Anode: Bromine gas (Br₂)
  • Cathode: Copper metal (Cu)
• What is the purpose of using inert electrodes in the electrolysis of copper bromide?


  To prevent the electrodes from reacting with the electrolyte.
• Why is it important to balance the number of electrons in half equations?


  To ensure the overall charge is conserved in the reaction.
• What is the process of electrolysis used for in aqueous solutions?


  To discharge ions from soluble compounds
• Why is copper discharged during electrolysis?


  Because it is less reactive than hydrogen
• What happens to copper ions at the cathode during electrolysis?


  Copper gains 2 electrons
• What does the anode discharge when no group 7 elements are present?


  Hydroxide ions
• What is the result of hydroxide ions giving up electrons at the anode?


  It forms oxygen gas
• What type of ions does the cathode attract during electrolysis?


  Positive ions
• Which ion is discharged at the cathode if sodium is present?


  Hydrogen ions
• Why does chlorine get discharged at the anode?


  Because it is in group 7
• What happens to chloride ions at the anode during electrolysis?


  They lose 1 electron to become chlorine gas
• What are the general rules for discharging ions during electrolysis?


  • The ion of the least reactive element will be discharged.
  • If a group 7 element is present, it will be discharged.
  • If no group 7 element is present, hydroxide ions (OH) are discharged.
• What is the process of electrolysis used for in aqueous solutions?


  It is used to discharge compounds in solution.
• Why is copper discharged during electrolysis?


  Because it is less reactive than hydrogen.
• What happens to copper ions at the cathode during electrolysis?


  Copper gains 2 electrons and accumulates at the cathode.
• What is discharged at the anode when no group 7 elements are present?


  Hydroxide ions are discharged.
• What does the hydroxide ion do at the anode during electrolysis?


  It gives up electrons to form oxygen gas.
• What attracts positive ions during electrolysis?


  The cathode attracts positive ions.
• Which ion is discharged at the cathode?


  The ion of the least reactive element is discharged.
• What attracts negative ions during electrolysis?


  The anode attracts negative ions.
• What happens if a group 7 element is present during electrolysis?


  The group 7 element will be discharged at the anode.
• What is discharged at the anode if no halogen is present?


  Hydroxide ions are discharged.
• What is the result of sodium being more reactive than hydrogen during electrolysis?


  Hydrogen is discharged at the cathode.
• What happens to hydrogen ions at the cathode?


  They gain an electron to form hydrogen gas.