Thermodynamics: Laws, Enthalpy, Entropy, and Gibbs Free Energy
Thermodynamic Processes
A thermodynamic process is the transformation of a system from an initial state of equilibrium to a final state of equilibrium. A system is in equilibrium when it meets the following conditions:
- Chemical Equilibrium: The composition does not change.
- Mechanical Equilibrium: No macroscopically observable movements occur.
- Thermal Equilibrium: The temperature is uniform throughout the system.
These changes can be:
- Reversible: The transformation occurs through a succession of equilibrium
Oxidation and Corrosion: Types, Causes, and Protection Methods
Oxidation and Corrosion
Oxidation
If a substance combines with oxygen, the process is called oxidation, and the resulting combination is called rust.
Examples: film, forge (Fe2O2), carbon dioxide (CO2), aluminum oxide (Al2O3).
Oxidation also releases heat. The more rapid the oxidation, the higher the temperatures reached.
A very rapid oxidation, with a strong development of light and heat, is called combustion.
When oxygen is removed from an oxide, it is called reduction.
Examples: mercury oxide decomposition,
Read MoreMaterials Science: Properties, Degradation, and Shaping Processes
Materials Science
Atomic Structure and Bonding
Atomic Number: Represents the number of protons in an element’s nucleus.
Alloy: A combination of two or more materials, often metals, designed to improve specific characteristics.
Polymer: Materials formed by combining organic molecules into long chains.
Interatomic Spacing: In solids, this refers to the apparent diameter of an atom.
Binding Energy: The energy needed to separate two atoms, reflecting the strength of their bond.
Avogadro’s Number: The number
Read MorePhysical & Chemical Properties of Matter: Atomic Structure Models
Physical Properties of Matter
A physical property is a characteristic that can be observed or measured without changing the substance’s composition. These properties are often revealed during physical processes like changes in state, temperature, or pressure.
Examples include color, hardness, density, boiling point, and melting point.
Physical properties are categorized as:
- Electrical
- Magnetic
- Optical
- Thermal
- Mechanical
Physical properties can be general or specific:
- General properties apply to various substances,
Understanding Matter: A Guide to Pure Substances, Mixtures, and Atomic Structure
Pure Substances and Mixtures
A pure substance is a type of matter with a defined and invariant composition and properties. Examples include table salt, gold, and oxygen.
A mixture consists of two or more substances, called components. Its composition is not defined, and its properties depend on the type and proportion of its components. Examples include seawater, air, and paint.
Types of Mixtures
Heterogeneous Mixtures
In a heterogeneous mixture, particles of different substances are visible with the
Read MoreStates of Matter: Exploring Solids, Liquids, and Gases
Behavior of Matter
What is a Model?
A model is a tool we use to represent something that is too big, too small, or too complex for us to handle directly.
Example of a Model
A globe is an example of a model.
Differences Between the 3 Phases of Matter
- Mobility of the particles
- Distance between particles
Relationship Between Heat, Kinetic Energy, and Change of State
By providing heat, the kinetic energy (or energy of motion) of molecules increases. The distance between the particles also increases, and finally,
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