Y10 Chem L25 Electrolysis

Which of the following half-equations are correct?

• O^2- → O + 2e^-

• 2 O^2- → O₂ + 4e^-

• O^2- + 2e^- → O

• 2 O^2- + 4e^- → O₂

Which of the following would produce potassium and chlorine?

• Electrolysis of dilute aqueous potassium chloride

• Electrolysis of molten potassium chloride

• Electrolysis of concentrated aqueous potassium chloride

• Electrolysis of solid potassium chloride

Which of the following half-equations take place at the cathode during the electrolysis of molten lead(II) bromide?

• Pb⁺² + 2e^- → Pb

• 2 Br^- → Br₂ + 2e^-

• Pb → Pb⁺² + 2e^-

• Br₂ + 2e^- → 2 Br^-

Which of the following half-equations take place at the anode during the electrolysis of aqueous copper(II) sulfate?

• Cu⁺² + 2e^- → Cu

• 4 OH^- → O₂ + 2H₂O + 4e^-

• 2H⁺ + 2e^- → H₂

• SO₄^2- + 2H⁺ + 2e^- → SO₃^2- + H₂O

Which of the following is NOT a product of the electrolysis of brine, a saturated sodium chloride solution?

• Chlorine

• Sodium hydroxide

• Hydrogen

• Sodium

Which of the following produces oxygen gas?

A) Electrolysis of aqueous potassium nitrate
B) Electrolysis of water

• A and B

• A does

  B doesn't

• A doesn't

  B does

• Neither A or B

Which of the following does NOT produce hydrogen?

• Electrolysis of sulfuric acid

• Electrolysis of aqueous silver nitrate

• Reaction between magnesium and hydrochloric acid

• Reaction between zinc and sulfuric acid

What happens to the mass of the cathode during the electrolysis of aqueous copper (II) sulfate using copper electrodes, and what happens to the colour of the solution?

• Cathode increases mass
  Solution stays blue

• Cathode decreases mass
  Solution stays blue

• Cathode increases mass
  Solution loses blue colour

• Cathode decreases mass
  Solution loses blue colour