Limitations Of First Law of Thermodynamics

First law of thermodynamics was developed empirically over about half a century. The first full statements of the law came in 1850 from RUDOLF CLAUSIUS and WILLIAM RANKINE. Rankine's statement was perhaps not quite as clear and distinct as was CLAUSIUS.
First law of Thermodynamics is an extension of the law of conservation of energy. Energy cannot created but it can be transferred from one form to another. The two forms considered in the first law are Heat and Work. Thus, the first law of thermodynamics deals with the energy of a system (typically, internal energy) and its interaction with its surroundings across the boundary in the form of heat and work transfer.

GENERAL STATEMENT OF FIRST LAW OF THERMODYNAMICS
........."The total energy of an isolated system or the universe (sum of system and surrounding) is constant or remains the same. Though it may be exchanged between system and surrounding. But It neither increases nor decreases"...........
The chemical energy of the cracker(rocket) is converted to heat and sound energy in the sky.
Well, this is an example of first law of thermodynamics.

LIMITATIONS OF FIRST LAW OF THERMODYNAMICS
1. First law of thermodynamics tells us that energy is conserved and it can neither be created nor destroyed. That means, every conservation of energy is possible,
   Like, heat ➝ work and work➝heat
But, heat can't be completely converted into work. Like, Water flows from higher levels to lower levels but the flow cannot be reversed.
First Law Of Thermodynamics Does Not Say Anything About It.
2. It does not tell us about the direction in which the process is taking place. Therefore, it is unable to predict whether a process will occur or not.
For example- The first law of thermodynamics tells us that heat transfer occurs between two bodies at different temperatures but it does not tell us in which direction the heat transfer occurs.
3. The first law of thermodynamic provides a necessary but not the sufficient condition for a process to occur.
4. First law says nothing whether the process is a spontaneous process or not.

!!In Order To Solve All These Limitations Of First Law Of Thermodynamics, The Second Law Of Thermodynamics Was Discovered!!


Hope you have found this article helpful!!
Do you have suggestions? Please write in comment box!!!
Feel free to comment if you have any queries!!

Comments

Post a Comment

Most Viewed Posts

Zeroth Law Of Thermodynamic: The Thermal Equilibrium Law

Image
In thermodynamics, we will see two types of walls. One is the Diathermic wall and the other is the adiabatic wall. Let us now go through them one by one.  • So the first is the Diathermic wall- " A Diathermic wall is a wall that allows the easy exchange of heat between two bodies (or between two systems or between system and surrounding) but does not allow the exchange of mass between them ". This means that it is a good conductor of heat. It is sometimes called as metallic wall because it is made of metal. • While the other is the adiabatic wall- " An Adiabatic wall is that wall which neither allows exchange of heat nor mass between two systems (or between system and surrounding) ". Since there is no exchange of heat and mass between the system and its surroundings, the system remains insulated from its surroundings. ➛ That's why whenever we separate the two systems by an adiabatic wall, then there is no concept of equilibrium between them. But whenever we sep...
Read more

Characteristics Of Entropy

Image
Entropy is an intrinsic property of a substance and is not affected by the external position of a system or its motion relative to other systems. It is a measure of the randomness of the system. Thus, the higher the randomness of the system, the higher the entropy of the system and the lower the randomness of the system, the lower the entropy of that system. Entropy   " Entropy is defined as a measure of the system's thermal energy that is incapable of doing work ". It is a state function.  For Example Heat is a form of energy that is incapable of doing work. Therefore, the more heat added to the system (or tranfer from the system), the higher (or the lower) will be its entropy.  The formula for change in entropy is given by the equation;                      ➩ ∆S = ∆Q/T For a reversible process, the change in entropy is given as; The Total Change In Entropy Entropy change is zero at equilibrium condition or whenev...
Read more

Reversed Carnot Cycle

Image
We have already discussed the concept of “ Carnot Cycle ”   & “ Its Efficiency ” and we have also seen the concept of “ Carnot Theorem And Its Explanation ” in our previous post. As we have already discussed that the Carnot Cycle is a reversible cycle and every process in the Carnot cycle is a reversible process. Therefore, every process of the Carnot cycle can be reversed. And the cycle can be operated in the opposite direction as well. In this article, we're interested in learning more about the reversed Carnot cycle, also known as the reversed Carnot heat engine cycle. Reversed Carnot Heat Engine It is important to note that if a reversible process is reversed, all related energy types—such as heat energy or work energy—will have the same magnitude but the direction of their interaction with matter will be changed. Let us first look at the Reverse Carnot Heat Engine  cycle here; The reversed Carnot heat engine cycle is depicted in the following figure. According to the...
Read more