Electrolysis MC diagnostic 1

Why does a compound have to be in a liquid or aqueous state to be electrolysed?

• So the ions are free to move

• So the electrons are free to move

• So the atoms are free to move

• So the electrons and ions are free to move

When molten aluminium oxide is electrolysed, what is the half equation at the positive electrode?

• Al³⁺ + 3e^- --> Al

• 4OH^- --> O₂ + 2H₂O + 4e^-

• O^2- --> O₂ + 2e^-

• 2O^2- --> O₂ + 4e^-

Copper (II) ions are represented as Cu²⁺. What does this mean?

• Each copper atom has gained 2 electrons

• Each copper atom has gained 2 protons

• Each copper atom has lost 2 electrons

• Copper molecules have lost 2 electrons

Copper (II) ions reduce to copper during the electrolysis of CuCl_2(l). What is the half equation?

• Cu²⁺ + 2e --> Cu

• Cu²⁺ - 2e --> Cu

• Cu²⁺ --> Cu + 2e^-

• Cu²⁺ + 2e^- --> Cu

What is the half equation for oxidation of oxide ions?

• O^- + e^- --> O₂

• 2O^2- --> O² + e^-

• 2O^2- --> O₂ + 2e^-

• 2O^2- --> O₂ + 4e^-

How are chloride ions represented?

• Cl

• Cl^-

• Cl₂

• Cl⁺

Chloride ions oxidise to chlorine during the electrolysis of molten CuCl₂. What is the half equation?

• Cl^- + e --> Cl

• Cl^- --> Cl₂ + e^-

• 2Cl^- --> Cl₂ + 2e^-

• 2Cl^- + 2e^- --> Cl₂

Copper (II) chloride solution electrolyses. What are the products at the electrodes?

• Cathode: copper ions

  Anode: chloride ions

• Cathode: copper

  Anode: chloride

• Cathode: copper

  Anode: chlorine

• Positive electrode: copper

  Negative electrode: chlorine

Which ions are discharged during the electrolysis of salt water?

• Cl^-

  H⁺

• Chloride ions

  Sodium ions

• Chlorine

  Hydrogen gas

• Cl₂

  H⁺

Which gas is produced at the positive electrode during the electrolysis of CuSO₄(aq)?

• Hydroxide​

• Hydrogen

• ​Oxygen

• Sulfur