Chapter 5 - Galvanic & Fuel Cells Flashcards
Alkaline Cell
A fuel cell which has an alkaline (OH⁻) electrolyte.
Battery
A series of galvanic cells connected together.
Anode
The electrode where oxidation occurs (strongest reducing agent). Note: electrons flow from anode to cathode.
Cathode
The electrode where reduction occurs (strongest oxidising agent). Note: cations move towards the cathode.
Circular Economy
An economy in which raw materials are recycled and reused once they have been used to make a product (as opposed to throwing them away).
Discharge
The giving out of electricity by converting chemical energy into electrical energy.
Electrochemical Series
A list of elements arranged in order of their standard electrode potentials.
Electrode
The solid conductor in a half cell, such as a metal rod or graphite.
Electrolyte
A liquid or gel which conducts electricity in a half cell through the movement of ions.
External Circuit
The connecting wires between the two electrodes in a half cell, which transfers electrons.
Fuel Cell
A type of galvanic cell in which the reactants (oxygen and a fuel) are supplied continuously. Oxygen is always the oxidizing agent and is found at the cathode. Overall equation = combustion. Electrodes are porous and catalytic.
Galvanic Cell (Voltaic Cell)
An electrochemical cell which converts the chemical energy of redox reactions into electrical energy. Consists of an anode, cathode and salt bridge.
Galvanometer
An instrument measuring electrical current in amps (note: unlike an ammeter, also tells the direction of the current).
Half-Cell
An electrode immersed in an electrolyte solution, where either reduction or oxidation occurs.
Hydrogen Economy
A future where hydrogen, produced from renewable feedstocks, serves as a primary source of electricity.
Internal Circuit
The salt bridge and electrolyte in a galvanic cell, which transmits ions.
Linear Economy
An economy in which raw materials are thrown away after use.
Potential Difference
The difference in electric potential energy between two points in an electric circuit, measured in volts (V).
Salt Bridge
The connection between the anode and cathode in a galvanic cell, which completes the circuit by allowing for positive and negative ions to move between the half cells.
Primary Cell
An electrochemical cell which produces an irreversible reaction and cannot be recharged.
Secondary Cell
An electrochemical cell which can be recharged.
Standard Hydrogen Electrode (SHE)
The half cell containing H2(g) and H⁺(aq).
Standard Electrode Potential (E°)
The potential difference between a half cell and the standard hydrogen electrode. Positive value = half cell is positive when connected to hydrogen.
Direct Redox Reaction
A spontaneous reaction which occurs between the oxidising agent and reducing agent when they are mixed together (as opposed to separated by half cells).
