Corrosion Chemistry and Electrochemical Series

A series that arranges metals and alloys in order of their corrosion tendencies in a specific environment, typically seawater.

The electrochemical series ranks metals based on their tendency to lose electrons (oxidize) in a standard solution.

Metals higher in the galvanic series are more anodic and corrode faster. Think of them as willing to donate electrons.

Metals lower in the galvanic series are more cathodic and resist corrosion. They're less eager to donate electrons.

The tendency for a metal to lose electrons and corrode in a specific environment. More anodic metals corrode faster.

A reference electrode used in the galvanic series, typically immersed in a solution like seawater.

The potential difference between a metal and the reference electrode, measured in volts.

A measure of the tendency for a metal to lose electrons in a standard solution. The more positive the standard reduction potential, the less likely the metal is to corrode.

The tendency of a metal to lose electrons and corrode is predicted by its position in the electrochemical series.

The ease with which a metal can displace another metal from a solution is predicted by its position in the electrochemical series.

Lithium-ion batteries use a layered crystal structure in the positive electrode for lithium storage.

In a lithium-ion battery, lithium ions are extracted from the positive electrode during charging, leaving behind a higher oxidation state for the transition metal.

The negative electrode in a lithium-ion battery is made up of graphite, which intercalates lithium ions during charging.

During charging, lithium ions migrate from the positive electrode to the negative electrode through the electrolyte, getting reduced and inserted into the graphite layers.

Lithium-ion batteries do not contain pure lithium metal in the negative electrode, it just contains lithium ions intercalated within the graphite layers.

The full charging of a lithium-ion battery can lead to the formation of lithium dendrites which can cause short circuits and safety hazards.

A type of fuel cell where the fuel is hydrogen gas and the electrolyte is phosphoric acid. The anode is where hydrogen gets oxidized, releasing protons (H+) and electrons. The electrons flow through an external circuit, powering the device.

An electrical device that converts chemical energy into electrical energy through a chemical reaction involving a fuel (typically hydrogen) and an oxidant (typically oxygen). It generates electricity without combustion.

In a fuel cell, the anode is where the fuel (e.g., hydrogen) gets oxidized, releasing protons (H+) and electrons.

In a fuel cell, the cathode is where the oxidant (e.g., oxygen) is reduced, combining with protons (H+) and electrons to produce water.

The process of losing electrons in a chemical reaction, usually resulting in a more positive oxidation state. In a fuel cell, this happens at the anode.

The process of gaining electrons in a chemical reaction, usually resulting in a more negative oxidation state. In a fuel cell, this happens at the cathode.

The movement of ions (charged atoms or molecules) through an electrolyte, making it possible for the chemical reaction to occur and produce electricity.

Calomel electrode is a type of reference electrode commonly used in electrochemical experiments. It is composed of mercury in contact with a solution containing mercury(I) chloride (calomel) and potassium chloride.

The Nernst equation relates the electrode potential of a half-cell to the standard electrode potential, the temperature, and the concentration of the reactants and products.

The potential of the Calomel electrode changes depending on the concentration of the potassium chloride solution, making it sensitive to solution changes.

When the potential of the coupled electrode is greater than the Calomel electrode, the Calomel electrode undergoes oxidation. The reverse reaction happens if the coupled electrode has a lower potential.

Oxidation occurs when a substance loses electrons. In a coupled system, the Calomel Electrode undergoes oxidation if the potential difference promotes electron loss.

The Calomel Electrode's potential varies depending on the concentration of the potassium chloride (KCl) solution. A saturated KCl solution is frequently used because it ensures a stable and consistent potential.

The calomel electrode can act as either an anode or a cathode, depending on the potential of the other electrode in the circuit. If the coupled electrode's potential is lower, the calomel electrode will undergo reduction, acting as the cathode.

In electrochemistry, a reference electrode is an electrode with a stable and well-defined potential. This potential is used as a reference to measure the potential of other electrodes in a circuit.

Hg(l) | Hg2Cl2(s), KCl(satd) | Pt is the standard representation of a saturated calomel electrode. It shows mercury and calomel in contact with a saturated potassium chloride solution, connected to a platinum wire for electrical contact.

The energy conversion efficiency is the ability of a device to convert one form of energy to another efficiently. In the context of fuel cells, it is the ratio of electrical energy produced to the chemical energy stored in the fuel, typically expressed as a percentage. Higher efficiency implies less energy is wasted as heat.

A fuel cell is a device that converts the chemical energy of a fuel into electrical energy through a chemical reaction. It typically involves the reaction of a fuel, such as hydrogen, with an oxidant, such as oxygen, to produce electricity, heat, and water.

A hydrogen-oxygen fuel cell is a type of fuel cell that utilizes the reaction between hydrogen and oxygen to generate electricity. It typically consists of an anode, a cathode, and an electrolyte, where hydrogen is oxidized at the anode and oxygen is reduced at the cathode, generating a flow of electrons through an external circuit.

The standard hydrogen electrode (SHE) is a reference electrode used in electrochemistry. It is defined as having a potential of 0.00 volts at all temperatures. It serves as a basis for measuring the relative potentials of other electrodes.

The calomel electrode's construction involves a glass tube. At the bottom, there's mercury, topped with a paste of mercurous chloride (calomel). This paste sits in a solution of potassium chloride (KCl). The mercury, calomel, and KCl solution create a stable potential difference, making it a reliable reference electrode.

Advantages of hydrogen-oxygen fuel cells are high efficiency, low pollution, quiet operation, and continuous energy supply. They are also lightweight, making them ideal for applications like spacecraft. The water byproduct can even be used for drinking in space.

Disadvantages of hydrogen-oxygen fuel cells include the difficulty in finding suitable, durable catalysts, challenges in storing and handling hydrogen gas, electrolyte corrosiveness, the need for extremely pure fuels, and high costs.