electrolytic cells

What drives the redox reaction in an electrolytic cell

An external electrical potential difference provides the energy for a non spontaneous redox reaction.

How does energy conversion in electrolytic cells differ from galvanic cells

Electrolytic cells convert electrical energy into chemical energy.

In an electrolytic cell, where does oxidation occur

At the anode which is connected to the positive terminal of the power source.

In an electrolytic cell, where does reduction occur

At the cathode which is connected to the negative terminal of the power source.

In which direction do electrons flow in an electrolytic cell

From the anode to the cathode through the external circuit.

How are the anode and cathode determined in an electrolytic cell

By the external power source, not by reduction potential.

How does the position of half reactions on the SEP table differ from galvanic cells

In electrolytic cells the oxidation half reaction is below and the reduction half reaction is above.

What is the sign of E°cell for an electrolytic cell

Negative.

How many beakers are typically used in an electrolytic cell

One beaker because there is no current generated and no salt bridge needed.

List three major applications of electrolysis

Metal production, metal purification, and metal plating.

What is observed at the cathode during the electrolysis of molten NaCl

Silvery shiny sodium metal forms near the cathode.

What is observed at the anode during the electrolysis of molten NaCl

Gas bubbles are produced indicating chlorine gas.

What is the overall reaction for the electrolysis of molten NaCl

2Na⁺(l) + 2Cl⁻(l) → 2Na(l) + Cl₂(g).

Why is a porous screen used during the electrolysis of molten NaCl

To prevent sodium metal and chlorine gas from reacting while allowing ion movement.

What products are formed at the cathode and anode during the electrolysis of molten NaCl

Sodium metal at the cathode and chlorine gas at the anode.

How does the electrolysis of aqueous NaCl differ from molten NaCl

The presence of water allows competing half reactions that may produce hydrogen at the cathode and chlorine or oxygen at the anode.

What determines which species is discharged at the electrodes during electrolysis of aqueous solutions

Standard electrode potential values and the nature and concentration of the electrolyte.

What is a key industrial use of electrolytic cells involving molten NaCl

Production of sodium metal and chlorine gas in the Downs cell.

What is a key use of electrolytic cells in everyday manufacturing

Electroplating metals to improve appearance or resistance to corrosion.

What are the essential components of an electrolytic cell

A power source, positive and negative electrodes, an electrolyte, and conducting wires.

What are the products at the cathode and anode during the electrolysis of molten NaCl

Sodium metal at the cathode and chlorine gas at the anode.

Which ion is reduced at the cathode during molten NaCl electrolysis

Na⁺ is reduced to sodium metal.

Which ion is oxidised at the anode during molten NaCl electrolysis

Cl⁻ is oxidised to chlorine gas.

Why does sodium form at the cathode in molten NaCl

Sodium ions have no competing reduction reactions in molten salt.

Why does chlorine gas form at the anode in molten NaCl

Chloride ions are the only anions present and are oxidised.

What visual observation confirms chlorine gas at the anode in molten NaCl

Bubbling and gas formation at the positive electrode.

What are the main products at the cathode and anode during the electrolysis of aqueous NaCl

Hydrogen gas at the cathode and chlorine gas at the anode.

Why is hydrogen gas formed at the cathode during aqueous NaCl electrolysis instead of sodium

Hydrogen ions are more easily reduced than sodium ions based on standard electrode potentials.

Why is chlorine gas formed at the anode during aqueous NaCl electrolysis

Chloride ions are discharged more readily than hydroxide ions.

What happens to the pH of the solution during aqueous NaCl electrolysis

The solution becomes basic as OH⁻ ions accumulate.

What are the products at the cathode and anode during the electrolysis of CuSO₄ using inert electrodes

Copper metal at the cathode and oxygen gas at the anode.

Why does copper deposit at the cathode during CuSO₄ electrolysis

Cu²⁺ has a higher reduction potential than water, so it is reduced first.

Why is oxygen gas produced at the anode during CuSO₄ electrolysis

Water is oxidised at the anode because sulfate ions are not easily oxidised.

What are the half equations for CuSO₄ electrolysis with inert electrodes

Cu²⁺ + 2e⁻ → Cu at the cathode, 2H₂O → O₂ + 4H⁺ + 4e⁻ at the anode.

What are the products at the cathode and anode during the purification of copper using copper electrodes

Pure copper is deposited at the cathode and impure copper dissolves at the anode.

Why does the anode decrease in mass during copper refining

The impure copper anode dissolves into solution as Cu²⁺.

Why does the cathode increase in mass during copper refining

Copper ions from the solution are reduced and plated onto the cathode.

What happens to the impurities during copper refining

Impurities either remain in solution or fall to the bottom as anode sludge.

What determines which species is discharged at each electrode in aqueous electrolysis

Standard electrode potential values and ion concentrations.

Why is predicting electrolysis products important in industry

To control which substances are produced at each electrode for efficiency and safety.

What is the cathode half equation for molten NaCl electrolysis

Na⁺(l) + e⁻ → Na(l).

What is the anode half equation for molten NaCl electrolysis

2Cl⁻(l) → Cl₂(g) + 2e⁻.

What is the cathode half equation for aqueous NaCl electrolysis

2H₂O(l) + 2e⁻ → H₂(g) + 2OH⁻(aq).

What is the anode half equation for aqueous NaCl electrolysis

2Cl⁻(aq) → Cl₂(g) + 2e⁻.

What is the cathode half equation for CuSO₄ electrolysis with inert electrodes

Cu²⁺(aq) + 2e⁻ → Cu(s).

What is the anode half equation for CuSO₄ electrolysis with inert electrodes

2H₂O(l) → O₂(g) + 4H⁺(aq) + 4e⁻.

What happens at the electrodes during copper refining

The anode dissolves as Cu(s) → Cu²⁺(aq) + 2e⁻ and the cathode plates Cu²⁺(aq) + 2e⁻ → Cu(s).