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For example, an ideal fuel cell operating at a temperature of 25 °C having gaseous hydrogen and gaseous oxygen as inputs and liquid water as the output could produce a theoretical maximum amount of electrical energy of 237.129 kJ (0.06587 kWh) per gram mol (18.0154 gram) of water produced and would require 48.701 kJ (0.01353 kWh) per gram mol ...
However, the same reaction can be carried out in a galvanic cell, allowing some of the chemical energy released to be converted into electrical energy. In its simplest form, a half-cell consists of a solid metal (called an electrode ) that is submerged in a solution; the solution contains cations (+) of the electrode metal and anions (−) to ...
An electrochemical cell is a device that generates electrical energy from chemical reactions. Electrical energy can also be applied to these cells to cause chemical reactions to occur. [1] Electrochemical cells that generate an electric current are called voltaic or galvanic cells and those that generate chemical reactions, via electrolysis for ...
There are many different machines and transducers that convert one energy form into another. A short list of examples follows: ATP hydrolysis (chemical energy in adenosine triphosphate → mechanical energy) Battery (electricity) (chemical energy → electrical energy) Electric generator (kinetic energy or mechanical work → electrical energy)
Batteries convert the chemical energy of the two metals (electrodes) interacting with the acid on the matboard (electrolyte) into electrical energy. In this situation, the metal surface serves as the electrode and an electric current (movement of electrons from one metal to the other) is created when the wire connects both metal surfaces.
The alkaline fuel cell (AFC) or hydrogen-oxygen fuel cell was designed and first demonstrated publicly by Francis Thomas Bacon in 1959. It was used as a primary source of electrical energy in the Apollo space program. [41] The cell consists of two porous carbon electrodes impregnated with a suitable catalyst such as Pt, Ag, CoO, etc.
During operation of an electrochemical cell, chemical energy is transformed into electrical energy. This can be expressed mathematically as the product of the cell's emf E cell measured in volts (V) and the electric charge Q ele,trans transferred through the external circuit. Electrical energy = E cell Q ele,trans
The amount of electrical energy that must be added equals the change in Gibbs free energy of the reaction plus the losses in the system. The losses can (in theory) be arbitrarily close to zero, so the maximum thermodynamic efficiency equals the enthalpy change divided by the free energy change of the reaction. In most cases, the electric input ...