An endergonic reaction is a type of chemical reaction that requires an input of energy to proceed. In these reactions, the free energy of the products is greater than the free energy of the reactants, which means that the overall change in free energy (ΔG) is positive. This characteristic indicates that the reaction is not spontaneous; it won't occur without an external source of energy. Endergonic reactions are common in biological systems.
An exergonic process is a type of chemical or physical reaction that releases energy during the reaction. The term "exergonic" is derived from the Greek words "ex-" meaning "out of" and "ergon" meaning "work" or "energy." In an exergonic reaction, the Gibbs free energy of the products is lower than that of the reactants, which means that the reaction can occur spontaneously under suitable conditions.
A "gas slug" generally refers to a discrete volume of gas that is contained within a pipeline or reservoir, often in the context of gas production, storage, or transportation. It can also relate to the movement of gas in a system where slugs of gas sometimes form as they travel through liquid or other phases in a multiphase flow system.
Isentropic nozzle flow refers to the flow of a compressible fluid (such as a gas) through a nozzle under idealized conditions where the process is isentropic. An isentropic process is one that is both adiabatic (no heat transfer occurs with the surroundings) and reversible (no entropy is generated). In simpler terms, it is an idealized process that assumes no friction and no heat loss, making it highly efficient.
Compressibility is a property of materials that describes their ability to change volume under pressure. Specifically, it refers to the measure of how much a given volume of a substance decreases when subjected to an increase in pressure. This property is particularly significant in the study of gases, but it can also apply to liquids and solids to varying extents.
Heat capacity is a physical property of a substance that measures the amount of heat energy required to change its temperature by a certain amount. It quantifies how much heat is needed to raise the temperature of a material based on its mass and specific heat capacity. There are two key concepts related to heat capacity: 1. **Specific Heat Capacity**: This is the amount of heat required to raise the temperature of one unit mass of a substance by one degree Celsius (or one Kelvin).
Heat flux, often denoted as \( q \), is the rate of heat transfer per unit area through a surface. It quantifies the amount of thermal energy that flows through a given surface area in a specific direction, typically expressed in units of watts per square meter (W/m²). Heat flux can occur through conduction, convection, and radiation: 1. **Conduction:** Involves heat transfer through materials due to temperature gradients.
The heat of vaporization (also known as enthalpy of vaporization) is the amount of energy required to convert a unit mass of a substance from a liquid into a vapor at a constant temperature and pressure. For elements, this value varies significantly and is typically measured in joules per gram (J/g) or kilojoules per mole (kJ/mol).
Electronic specific heat refers to the contribution of electrons to the specific heat capacity of a material, particularly in the context of metals and conductors at low temperatures. Specific heat is a measure of how much heat energy is required to change the temperature of a substance.
The entropy of fusion is a thermodynamic quantity that measures the change in entropy when a substance transitions from a solid phase to a liquid phase at a given temperature and pressure, typically at its melting point. This process involves the breaking of bonds or interactions that hold the solid structure together, leading to an increase in disorder or randomness, which is represented by an increase in entropy.
Internal pressure refers to the pressure that exists within a confined space, such as a container, vessel, or any system that holds a fluid (liquid or gas). This pressure is caused by the molecules of the substance interacting with each other and the walls of the container. Key points about internal pressure include: 1. **Definition**: Internal pressure is the force exerted by the molecules of a fluid on the walls of its container.
In the context of thermodynamics, material properties refer to the characteristics of a material that define its behavior in response to changes in temperature, pressure, and other environmental conditions. These properties are critical for understanding how materials will perform in various applications, particularly in areas such as engineering, materials science, and physics.
A partial molar property is a thermodynamic property of a component in a mixture that describes how that property changes when the number of moles of that component is varied while keeping the temperature, pressure, and the amounts of all other components constant. In essence, it provides insight into how the behavior of one component affects the overall properties of the mixture.
Soil thermal properties refer to the characteristics of soil that influence its ability to conduct and retain heat. Understanding these properties is essential for various applications, including agriculture, environmental science, and civil engineering. The key thermal properties of soil include: 1. **Thermal Conductivity**: This property measures how well soil can conduct heat. It is influenced by factors such as soil texture, moisture content, bulk density, and organic matter content.
Volumetric heat capacity, often denoted as \( C_v \), is a measure of a material's ability to store thermal energy per unit volume for a given temperature change. It quantifies how much heat is required to raise the temperature of a unit volume of a substance by one degree Celsius (or one Kelvin).
Benjamin Thompson (1753–1814), also known as Count Rumford, was an American-born physicist and inventor who made significant contributions to the fields of thermodynamics and the understanding of heat. He is best known for his work on the nature of heat and its relationship to mechanical work.
Gustav Zeuner (1819-1905) was a German engineer and inventor, primarily known for his work in the field of mechanical engineering and thermodynamics. He is most noted for his contributions to the understanding of steam engines and the development of various mechanical devices. His work laid foundational principles that are still referenced in engineering and thermodynamics today. One of Zeuner's significant contributions is the Zeuner cycle, which is a thermodynamic cycle related to heat engines.
The 19th century was a pivotal time for the development of physics, particularly in Britain, where several influential physicists made significant contributions to the field. Here are some notable 19th-century British physicists and their contributions: 1. **Michael Faraday (1791–1867)**: Often regarded as one of the most important experimentalists in the history of science, Faraday made substantial contributions to electromagnetism and electrochemistry.
In thermodynamics, a **state function** is a property of a system that depends only on the state of the system and not on the path taken to reach that state. This means that the value of a state function is determined solely by the current condition of the system (e.g., temperature, pressure, volume, internal energy, enthalpy, entropy, and Gibbs free energy) and is independent of how the system arrived at that condition.
Thermodynamic activity is a measure of the "effective concentration" of a species in a solution, taking into account interactions between particles. It provides a way to understand how the presence of other components in a mixture influences the behavior of a specific component compared to an ideal situation, where components behave independently. In ideal solutions, the activity (\(a\)) of a species is equal to its molar concentration (\(C\)).