Why Is Zeroth Law Called So?
Why Is Zeroth Law Called So?
Zeroth law of Thermodynamics:
It states that if Object A and Object C are in thermal equilibrium (that is, they are both at the same temperature or there is no energy flow in the form of heat between these two blocks), and if Object B and Object C is in thermal equilibrium with each other, then Object A and Object B will also be in thermal equilibrium.
If we see chronologically the order of laws of thermodynamics was first law, second law, third law, and at the end zeroth law.
- First law of Thermodynamics-
(i) This law mainly talks about the internal energy of an object. It cannot be created nor be destroyed, it can only be converted from one form of energy to another.
(ii) Later, it was found that this is also dependent on the temperature of the body.
(iii) Mainly this is quantitative law as it talks about the amount of internal energy.
2. Second law of Thermodynamics-
(i) This law tells about the state of entropy of the entire universe, as an isolated system (system + surroundings) will never decrease and can never be negative.
(ii) This is a qualitative law.
3. Third law of Thermodynamics-
(i) It says that absolute zero temperature can't be achieved.
(ii) It states that at absolute zero (0 Kelvin), a completely perfect (100 percent pure) crystalline structure will have zero entropy.
After stating these three laws scientists wanted a method to actually measure the temperature of the body as all three laws dealt with temperature. So, to measure temperature thermometer was discovered which used a simple thermometric concept that was called the zeroth law.
As Zeroth law was a fundamental law that was used further in the existing three laws. So, as per the importance perspective, this law was kept at the beginning.
Zeroth law of Thermodynamics:
It states that if Object A and Object C are in thermal equilibrium (that is, they are both at the same temperature or there is no energy flow in the form of heat between these two blocks), and if Object B and Object C is in thermal equilibrium with each other, then Object A and Object B will also be in thermal equilibrium.
If we see chronologically the order of laws of thermodynamics was first law, second law, third law, and at the end zeroth law.
- First law of Thermodynamics-
(i) This law mainly talks about the internal energy of an object. It cannot be created nor be destroyed, it can only be converted from one form of energy to another.
(ii) Later, it was found that this is also dependent on the temperature of the body.
(iii) Mainly this is quantitative law as it talks about the amount of internal energy.
2. Second law of Thermodynamics-
(i) This law tells about the state of entropy of the entire universe, as an isolated system (system + surroundings) will never decrease and can never be negative.
(ii) This is a qualitative law.
3. Third law of Thermodynamics-
(i) It says that absolute zero temperature can't be achieved.
(ii) It states that at absolute zero (0 Kelvin), a completely perfect (100 percent pure) crystalline structure will have zero entropy.
After stating these three laws scientists wanted a method to actually measure the temperature of the body as all three laws dealt with temperature. So, to measure temperature thermometer was discovered which used a simple thermometric concept that was called the zeroth law.
As Zeroth law was a fundamental law that was used further in the existing three laws. So, as per the importance perspective, this law was kept at the beginning.
