Thermodynamics - Definition, Properties, Process, FAQs

Thermodynamics is associated with the ideas of heat and temperature, as well as the exchange of heat and other forms of energy. The four principles of thermodynamics govern the behaviour of these quantities, which provide a quantitative description using quantifiable macroscopic physical characteristics also described by statistical mechanics in term of microscopic element..

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1. What is the definition of thermodynamics?
2. Properties of Thermodynamics
3. Process of Thermodynamics

The four rules of thermodynamics, which provide an axiomatic basis, are used to describe any thermodynamic system. The first law states that energy can be transferred across physical systems in the form of heat or work. The second law establishes the existence of a quantity known as entropy, which explains the thermodynamic direction in which a system might modifies as well as quantifies order of system, and work which can be extracted.

What is the definition of thermodynamics?

Thermodynamics Definition: Thermodynamics is a discipline of physics that studies heat, work, and temperature, as well as their relationships with energy, radiation, and matter's physical properties.

Different Thermodynamics Branches

The following are the four branches of thermodynamics:

• Classical Thermodynamics.
• Statistical Thermodynamics.
• Chemical Thermodynamics.
• Equilibrium Thermodynamics.

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Properties of Thermodynamics

Thermodynamic properties are defined as characteristics of a system that can be used to specify the state of the system. Thermodynamic properties can be broad or narrow.

1. Intensive properties are those that are independent of the amount of substance present. The qualities of temperature and pressure are both significant.
2. The value of extensive characteristics is proportional to the system's mass. Volume, energy, and enthalpy are all important properties to consider.

Zeroth law of thermodynamics.

Two thermodynamic systems in thermal equilibrium with a third system are in thermal equilibrium with each other independently, according to the zeroth law of thermodynamics.

Thermodynamics' First Law

Energy cannot be created or destroyed, according to the first law of thermodynamics, yet it can be converted from one form to another.

Thermodynamics' First Law: Examples

The first law of thermodynamics may seem abstract, but by looking at a few examples, we may have a better understanding of it.

Equation: ΔU = Q − W. Here ΔU is the change in internal energy U of the system.

Example: Light bulbs transform electrical energy into light energy (radiant energy).

Thermodynamics' Second Law

The second rule of thermodynamics states that entropy constantly increases in an isolated system. Any isolated system will advance toward thermal equilibrium, or maximum entropy, on its own. The universe's entropy is always increasing and never decreasing. Many people take this statement for granted, but it has a significant influence and consequence.

Thermodynamics' Second Law: Examples

If a room is not cleaned or tidied, it will become more cluttered and disordered over time. The entropy in the room drops when it is cleaned, but the effort to clean it has led in a rise in entropy outside the room that is more than the entropy lost.

Thermodynamics' Third Law.

When the temperature approaches absolute zero, the entropy of a system approaches a constant value, according to the third rule of thermodynamics.

To learn the third law of thermodynamics step by step, let's use steam as an example:

1. Its molecules are free to move about and have high entropy.
2. When the temperature is reduced to 100 °C, steam is transformed to water, which restricts the movement of molecules, lowering the entropy of water.
3. When water is chilled below 0 degrees Celsius, it solidifies as ice. The mobility of molecules is further constrained in this condition, and the system's entropy decreases.
4. The movement of the molecules in the ice is further constrained when the temperature of the substance drops and the entropy of the substance decreases.
5. The entropy should be zero when the ice is cooled to absolute zero. In actuality, cooling any substance to zero is impossible.

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Process of Thermodynamics

When there is an energetic shift within a system that is related with changes in pressure, volume, and internal energy, it is called a thermodynamic process.

There are four different types of thermodynamic processes, each with its own set of characteristics:

1. Adiabatic process - A adiabatic process is one in which no heat is transferred into or out of the system.
2. Isochoric Process - A process in which there is no change in volume and no work is done by the system.
3. Isobaric Process - When there is no change in pressure, the process is called isobaric.
4. Isothermal Process - A process in which the temperature does not change.

Properties: extensive and intensive

1. The value of an intensive property is independent of the amount or size of matter present in the system. Temperature, density, and pressure are only a few examples.
2. Extensive property: This is a property whose value is proportional to the amount or size of matter in the system. Consider the following examples: mass and total volume.

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