Electrochemistry and Electrolysis - Vocabulary Flashcards

Vocabulary flashcards covering oxidation-reduction concepts, electrochemical cells, electrolysis, electroplating, and copper electrolysis from the provided notes.

Oxidation

Loss of electrons during a chemical reaction; oxidation state increases.

Reduction

Gain of electrons during a chemical reaction; oxidation state decreases.

Oxidation number

A formal charge assigned to an element to track electron transfer in redox reactions.

OIL RIG

Mnemonic: Oxidation Is Loss of electrons; Reduction Is Gain of electrons.

Oxidising agent

A substance that oxidizes another substance by being reduced itself.

Reducing agent

A substance that reduces another substance by being oxidized itself.

Anode

Electrode where oxidation takes place; in electrolytic cells connected to the positive terminal.

Cathode

Electrode where reduction takes place; in electrolytic cells connected to the negative terminal.

Electrolyte

A substance that provides ions to carry current in solution; usually a salt, acid, or alkali.

Electrolytic cell

A cell that uses external electrical energy to drive a non-spontaneous redox reaction; oxidation at the anode and reduction at the cathode.

Electrolysis

The process of using electricity to drive a chemical change; converts electrical energy into chemical energy.

Inert electrodes

Electrodes that do not participate in the redox reaction (e.g., graphite, platinum); good conductors.

Copper sulfate (CuSO4) electrolyte

A copper-containing electrolyte used in copper electrolysis/plating; provides Cu2+ for deposition.

Anode mass loss

The anode tends to lose mass as it is oxidized and dissolves into the solution.

Cathode mass gain

The cathode gains mass as reduced metal is deposited from solution.

Electroplating

Process of depositing a thin layer of metal onto a surface by electrolysis.

Purification by electrolysis

Purifying metal (e.g., copper) by using two electrodes; impurities settle as sludge and the metal deposits at the cathode.

Decomposition (electrolysis)

Breaking a compound into ions by applying an electric current.

Chlorine gas formation

At the anode, chloride ions are oxidized to chlorine gas (Cl2) during copper electrolysis.

Copper deposition at the cathode

Cu2+ is reduced to Cu metal at the cathode (Cu2+ + 2e- → Cu).

Sludge (impurities)

Impurities that settle at the bottom of the beaker during electrolysis rather than depositing on the metal.

Homogeneous vs. heterogeneous electrolyte

Homogeneous electrolytes are uniform; heterogeneous electrolytes have different phases and can affect battery performance.

Graphite electrode

Inert, conductive electrode used in electroplating and electrolysis.

Platinum electrode

Inert, conductive electrode used when reactions require non-consumed electrodes.

Endothermic (electrolysis)

Process that absorbs energy; electrolysis is powered by electrical energy (requires input).

Non-spontaneous reaction

A reaction that does not proceed without external energy input (as in electrolysis).