Electrolysis Paper 1

What is produced at the cathode and anode during electrolysis of molten lead bromide (PbBr₂)?

Cathode: Lead (Pb); Anode: Bromine (Br₂)

What is produced at the cathode and anode during electrolysis of molten sodium chloride (NaCl)?

Cathode: Sodium (Na); Anode: Chlorine (Cl₂)

What is produced at the cathode and anode during electrolysis of copper chloride solution (CuCl₂)?

Cathode: Copper (Cu); Anode: Chlorine (Cl₂)

What is produced at the cathode and anode during electrolysis of sodium sulfate solution (Na₂SO₄)?

Cathode: Hydrogen (H₂); Anode: Oxygen (O₂)

What is produced at the cathode and anode during electrolysis of sulfuric acid (H₂SO₄)?

Cathode: Hydrogen (H₂); Anode: Oxygen (O₂)

What is produced at the cathode and anode during electrolysis of brine (concentrated NaCl solution)?

Cathode: Hydrogen (H₂); Anode: Chlorine (Cl₂)

What is produced at the cathode in aqueous solutions if the metal is more reactive than hydrogen?

Hydrogen gas (H₂)

What is produced at the cathode in aqueous solutions if the metal is less reactive than hydrogen?

The metal itself is deposited

What is produced at the anode in aqueous solutions if halide ions are present (Cl⁻, Br⁻, I⁻)?

The corresponding halogen gas (Cl₂, Br₂, or I₂)

What is produced at the anode in aqueous solutions if no halide ions are present?

Oxygen gas (O₂) from hydroxide ions (OH⁻)

What is the rule for predicting products at the cathode in aqueous electrolysis?

Compare the reactivity of the metal ion with hydrogen

What is the rule for predicting products at the anode in aqueous electrolysis?

Check if halide ions are present; if not, oxygen is produced