Connection Between Zeroth Law & Temperature

Do you wish to know which law of thermodynamics is related to the concept of temperature?

The four thermodynamic laws are the zeroth law of thermodynamics, the first law of thermodynamics, the second law of thermodynamics, and the third law of thermodynamics. Ralph H. Fowler created the zeroth law. It is worth highlighting that the zeroth law appeared after the three laws of thermodynamics. 

The zeroth law of thermodynamics showcases that when two objects are in thermodynamic contact with another entity, it is considered to be in thermal equilibrium with one another. Temperature is declared a fundamental and quantitative characteristic of matter by the zeroth law. We will study more about the definition of the zeroth law of thermodynamics and how the zeroth law of thermodynamics leads to the concept of temperature.

Definition of the zeroth law of thermodynamics

When two items or systems are in thermal equilibrium with a third object or system, they are said to be in thermal equilibrium with each other, according to the definition of the zeroth law of thermodynamics.

When two bodies come into contact and are separated by a heat-permeable barrier, they are said to be in thermal equilibrium; no heat transfer from one body to the other occurs. It simply indicates that the temperature of both bodies is the same. According to the Zeroth law, temperature is a fundamental and measurable feature of matter. 

Relation Between Temperature &  zeroth Law Of thermodynamics

Having understood the zeroth law of thermodynamics, it is essential to know how the zeroth law of thermodynamics leads to the concept of temperature.  A body’s temperature is a thermodynamic variable determining a surface’s degree of hotness or coldness. A hot object has a higher temperature than a cold object with a lower temperature. We know that thermal equilibrium is reached when two bodies in touch reach a constant temperature since the temperature is a relative variable. Heat is transferred from a hot thing to a colder item, or, to put it another way, hot objects lose heat energy while cold objects acquire it. When the exchange of heat energy between two bodies in thermal contact stops, the bodies reach a constant temperature and thus attain thermal equilibrium.

Mathematical theories frequently require an equivalence relation, which is a technique for determining whether two entities are the same or not. Because it allows for the mathematical concept of temperature and the presence of physical thermometers, the zeroth law is known as the equivalence relation of thermodynamics. The distinction between energy and temperature is an important notion. Knowing how much energy two separate items possess is insufficient to predict which way heat will travel when they come into contact. The direction of heat flow is determined by the relative temperatures of the two systems.

Thermal equilibrium occurs when two things are in close proximity to each other and allow one to obtain energy from the other without transferring net energy. If no net energy is transferred between them when they are placed in contact, they are in thermal equilibrium even when they are not in contact. When two objects remain in contact for a long time, they usually reach a point of equilibrium.

A transitivity assertion is the zeroth law of thermodynamics. The first, second, and third laws of thermodynamics were well-known. The zeroth law had never been mentioned before, but because it was the first to be investigated, Fowler gave it a lower number. This clearly states how the Zeroth law of thermodynamics leads to the concept of temperature.

Consider the case below: A thermometer is X. The zeroth law showcases that if X has a certain temperature while being in equilibrium with Y, and then it comes in contact with Z, then there will be no exchange of energy with Z. To put it another way, two items in thermal equilibrium have the same temperature. The fundamental relationship between temperature and thermal equilibrium is as follows.

A thermometer is a gadget that measures one’s own body temperature. We may declare that a thermometer measures the temperature of something else and interpret the statement that two items are at the same temperature using the notions of thermal equilibrium and the zeroth law of thermodynamics.

A thermometer is a device that displays known and calibrated properties based on its temperature. When mercury, for example, heats up, it expands in volume in a regular pattern. The temperature of an object can be determined by bringing a thermometer into thermal equilibrium with it and then measuring its properties, such as the amount of mercury that has expanded.

When attempting to compare the temperatures of two things, the zeroth law comes into play. When a thermometer is submerged in liquid, it achieves thermal equilibrium and reads a specific temperature. 

Conclusion

The zeroth law of thermodynamics states that when two items or systems are in thermal equilibrium with a third object or system, they are regarded to be in thermal equilibrium with each other.

When talking about the relationship between temperature and the zeroth law of thermodynamics, we can conclude that the zeroth law of thermodynamics defines temperature. Temperature is vital to assess because it affects whether or not heat exchange occurs between items, according to this law.