How many laws of thermodynamics are there?
There are four laws of thermodynamics which are listed as follows:
- Zeroth Law of Thermodynamics
- First Law of Thermodynamics
- Second Law of Thermodynamics
- Third Law of Thermodynamics
Zeroth Law of Thermodynamics
According to the Zeroth Law of Thermodynamics, if two bodies are separately in thermal equilibrium with a third body, then the first two bodies are likewise in thermal equilibrium with each other.
This indicates that if system A is in thermal equilibrium with system B, and system C is likewise in thermal equilibrium with system B, then both systems A and C are in thermal equilibrium.
Example showing Zeroth Law of Thermodynamics:
Imagine you have three containers of water, A, B, and C. Container A is at a temperature of 50°C, container B is at 60°C, and container C is at 70°C. Now, we want to determine if containers A, B, and C are in thermal equilibrium with each other based on the Zeroth Law.
Step 1: Confirm that A and C are in thermal equilibrium with the third system (B). To do this, we bring container B into contact with container A and check if no heat transfer occurs. After some time, no heat flows between A and B, indicating they have reached thermal equilibrium. Similarly, if we bring container B into contact with container C and find no heat transfer between them, it implies that C and B are also in thermal equilibrium.
Step 2: Now, we can conclude that A and C are in thermal equilibrium because they both meet the condition of being in thermal equilibrium with B. Therefore, by the Zeroth Law, A and C are in thermal equilibrium with each other as well.
So, based on the Zeroth Law, we can say that containers A, B, and C are all in thermal equilibrium with each other. This means that their temperatures can be considered equal on the same temperature scale, and we can measure temperature differences and changes accordingly.
First Law of Thermodynamics
Energy cannot be generated or destroyed, according to the first law of thermodynamics, but it can be converted from one form to another. Heat, internal energy, and work are all addressed by the first law of thermodynamics.
Energy cannot be generated or destroyed, according to the first law of thermodynamics, but it can be converted from one form to another. According to this law, some of the heat provided to the system is utilized to change the internal energy, while the remaining is used to perform work. First law of thermodynamics is also known as the law of conservation of energy.
Mathematical Form of First Law of Thermodynamics:
Mathematically, it may be expressed as
ΔQ = ΔU + W
Where,
The heat given or lost is denoted by ΔQ.
The change in internal energy is denoted by ΔU.
W stands for work done.
The above equation can alternatively be written as follows:
ΔU = ΔQ − W
As a result of the above equation, we may deduce that the quantity (ΔQ – W) is unaffected by the path taken to change the state. Furthermore, when heat is applied to a system, internal energy tends to rise, and vice versa.
Second Law of Thermodynamics
In an isolated system, the second law of thermodynamics asserts that entropy always increases. Any isolated system progresses spontaneously toward thermal equilibrium or the state of maximum entropy. The universe’s entropy is always increasing and never decreasing.
Read in Detail: Second Law of Thermodynamics
Third Law of Thermodynamics
The third law of thermodynamics states that when the temperature approaches absolute zero, the entropy of a system approaches a constant value. At absolute zero temperature, the entropy of a pure crystalline solid is zero. If the perfect crystal has only one state with minimum energy, this assertion holds true.
Thermodynamics
Thermodynamics is a branch of Physics that explains how thermal energy is changed to other forms of energy and the significance of thermal energy in matter. The behavior of heat, work, and temperature, along with their relations to energy and entropy are governed by the Four Laws of Thermodynamics.
Thermodynamics is the study of relations between heat, work, temperature, and energy, focusing on the laws that govern the transformation of energy within a system and its capability to perform work in its environment. These principles delineate how energy shifts within a system and assess the system’s potential to execute beneficial work.
In this article, we will learn about Thermodynamics, Branches of Thermodynamics, Laws of Thermodynamics, Basic Concepts of Thermodynamics, and Examples of Thermodynamics in Daily Life.
Table of Content
- What is Thermodynamics?
- Thermodynamics Definition
- Different Branches of Thermodynamics
- Classical Thermodynamics
- Statistical Thermodynamics
- Chemical Thermodynamics
- Equilibrium Thermodynamics
- Non-equilibrium Thermodynamics
- Basic Concepts of Thermodynamics
- Thermodynamic Systems
- Surroundings
- Heat
- Work
- Internal Energy
- Thermodynamic Properties or Variables
- Thermodynamic Equilibrium
- Thermal Equilibrium
- Thermodynamic Processes
- Thermodynamic Potentials
- What is Enthalpy?
- What is Entropy in Thermodynamics?
- Laws of Thermodynamics
- How many laws of thermodynamics are there?
- Zeroth Law of Thermodynamics
- First Law of Thermodynamics
- Second Law of Thermodynamics
- Third Law of Thermodynamics
- Thermodynamics Examples in Daily Life
- Thermodynamics Examples
- Thermodynamics Class 11
- Thermodynamics JEE Mains Questions