zeroth law of thermodynamics

(noun)

Let A, B and C be three systems. If A and C are in thermal equilibrium, and A and B are in thermal equilibrium, then B and C are in thermal equilibrium.

Related Terms

Examples of zeroth law of thermodynamics in the following topics:

  • The Zeroth Law of Thermodynamics

    • The Zeroth Law of Thermodynamics states that systems in thermal equilibrium are at the same temperature.
    • There are a few ways to state the Zeroth Law of Thermodynamics, but the simplest is as follows: systems that are in thermal equilibrium exist at the same temperature.
    • What the Zeroth Law of Thermodynamics means is that temperature is something worth measuring, because it indicates whether heat will move between objects.
    • However, according to the Zeroth Law of Thermodynamics, if the systems are in thermal equilibrium, no heat flow will take place.
    • There are more formal ways to state the Zeroth Law of Thermodynamics, which is commonly stated in the following manner:

  • A Review of the Zeroth Law

    • Zeroth law justifies the use of thermodynamic temperature, defined as the shared temperature of three designated systems at equilibrium.
    • This law was postulated in the 1930s, after the first and second laws of thermodynamics had been developed and named.
    • Zeroth law justifies the use of thermodynamic temperature : the common "label" that the three systems in the definition above share is defined as the temperature of the systems.
    • A brief introduction to the zeroth and 1st laws of thermodynamics as well as PV diagrams for students.
    • Discuss how the Zeroth Law of Thermodynamics justifies the use of thermodynamic temperature

  • The First Law of Thermodynamics

    • The first law of thermodynamics states that energy can be transferred or transformed, but cannot be created or destroyed.
    • The first law of thermodynamics deals with the total amount of energy in the universe.
    • The law states that this total amount of energy is constant.
    • According to the first law of thermodynamics, energy can be transferred from place to place or changed between different forms, but it cannot be created or destroyed.
    • Another useful form of the first law of thermodynamics relates heat and work for the change in energy of the internal system:

  • The Second Law

    • The second law of thermodynamics deals with the direction taken by spontaneous processes.
    • The first law of thermodynamics would allow them to occur—none of those processes violate conservation of energy.
    • The law that forbids these processes is called the second law of thermodynamics .
    • The already familiar direction of heat transfer from hot to cold is the basis of our first version of the second law of thermodynamics.
    • Contrast the concept of irreversibility between the First and Second Laws of Thermodynamics

  • The First Law

    • The 1st law of thermodynamics states that internal energy change of a system equals net heat transfer minus net work done by the system.
    • The first law of thermodynamics is a version of the law of conservation of energy specialized for thermodynamic systems.
    • In equation form, the first law of thermodynamics is
    • The change in the internal energy of the system, ΔU, is related to heat and work by the first law of thermodynamics, ΔU=Q−W.
    • Explain how the net heat transferred and net work done in a system relate to the first law of thermodynamics

  • The Three Laws of Thermodynamics

    • The laws of thermodynamics define fundamental physical quantities (temperature, energy, and entropy) that characterize thermodynamic systems.
    • The first law of thermodynamics, also known as Law of Conservation of Energy, states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another.
    • The second law of thermodynamics says that the entropy of any isolated system always increases.
    • A simple way to think of the second law of thermodynamics is that a room, if not cleaned and tidied, will invariably become more messy and disorderly with time - regardless of how careful one is to keep it clean.
    • The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero.

  • The Third Law

    • According to the third law of thermodynamics, the entropy of a perfect crystal at absolute zero is exactly equal to zero.
    • The third law of thermodynamics is sometimes stated as follows: The entropy of a perfect crystal at absolute zero is exactly equal to zero.
    • In simple terms, the third law states that the entropy of a perfect crystal approaches zero as the absolute temperature approaches zero.
    • This law provides an absolute reference point for the determination of entropy. ( diagrams the temperature entropy of nitrogen. ) The entropy (S) determined relative to this point is the absolute entropy represented as follows:
    • Absolute value of entropy can be determined shown here, thanks to the third law of thermodynamics.

  • The Third Law of Thermodynamics and Absolute Energy

    • The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero.
    • The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches zero.
    • A more general form of the third law applies to systems such as glasses that may have more than one minimum energy state: the entropy of a system approaches a constant value as the temperature approaches zero.
    • Physically, the law implies that it is impossible for any procedure to bring a system to the absolute zero of temperature in a finite number of steps.
    • The entropy (S) of a substance (compound or element) as a function of temperature (T).

  • The Second Law of Thermodynamics

    • The second law of thermodynamics states that every energy transfer increases the entropy of the universe due to the loss of usable energy.
    • The second law of thermodynamics explains why: No energy transfers or transformations in the universe are completely efficient.
    • Thermodynamically, heat energy is defined as the energy transferred from one system to another that is not doing work.
    • Since all energy transfers result in the loss of some usable energy, the second law of thermodynamics states that every energy transfer or transformation increases the entropy of the universe.
    • Explain how living organisms can increase their order despite the second law of thermodynamics

  • Changes in Energy

    • The concept of entropy evolved in order to explain why some processes (permitted by conservation laws) occur spontaneously while their time reversals (also permitted by conservation laws) do not; systems tend to progress in the direction of increasing entropy.
    • In classical thermodynamics the entropy is interpreted as a state function of a thermodynamic system.
    • The entropy of a system is defined only if it is in thermodynamic equilibrium.
    • The entropy of the thermodynamic system is a measure of how far the equalization has progressed.
    • The second law of thermodynamics shows that in an isolated system internal portions at different temperatures will tend to adjust to a single uniform temperature and thus produce equilibrium.