Electrochemistry studies the interconversion of electrical energy and chemical energy in redox reactions.

Oxidation (loss of electrons) occurs at the anode in an electrochemical cell.

The standard hydrogen electrode (SHE) has an assigned potential of 0 V and is the reference for all other electrode potentials.

Electrons flow from the anode (where oxidation occurs) to the cathode (where reduction occurs) through the external circuit.

The salt bridge allows ion flow to balance charges in the half-cells, maintaining electrical neutrality.

E^0_cell = E^0_red,cathode - E^0_red,anode, using standard reduction potentials for the cathode and anode.

Spontaneous reactions occur when a stronger reducing agent (Zn, E^0 = -0.76 V) reduces a stronger oxidizing agent (Cu^2+, E^0 = +0.34 V), yielding positive E^0_cell.

Faraday’s first law states that the mass of a substance deposited or liberated is directly proportional to the quantity of electricity (charge) passed.

Al^3+ + 3e^- -> Al. Depositing 1 mole of Al requires 3 moles of electrons, or 3 Faradays.

In a Daniell cell, copper acts as the cathode where reduction (Cu^2+ + 2e^- -> Cu) occurs.

A positive cell potential indicates a spontaneous redox reaction under standard conditions, per Delta G = -nFE^0.

Secondary cells, like lead-acid batteries, are rechargeable, unlike primary cells (e.g., dry cell, mercury cell).

E^0_cell = E^0_cathode - E^0_anode = 0.34 - (-0.76) = 1.10 V for a Zn (anode) and Cu (cathode) galvanic cell.

Corrosion involves oxidation of iron at the anode and reduction of oxygen at the cathode, an electrochemical process.

Lead-acid batteries use sulfuric acid as the electrolyte to facilitate ion movement between electrodes.

The salt bridge allows cations and anions to move to maintain charge neutrality in the half-cells.

A highly negative reduction potential (e.g., Zn, E^0 = -0.76 V) indicates a strong tendency to oxidize, making it a strong reducing agent.

In electrolysis, reduction occurs at the cathode where electrons are gained by ions or molecules.

The notation is anode | anode ion || cathode ion | cathode, with Zn as the anode (oxidation) and Cu as the cathode (reduction).

Painting creates a barrier, preventing iron from contacting moisture and oxygen, thus inhibiting corrosion.