Question about the thermodynamic temperature scale

In summary, the thermodynamic temperature scale is a measure of temperature based on the principles of thermodynamics, specifically the absolute zero point, where molecular motion ceases. It is commonly represented in Kelvin, where 0 K corresponds to absolute zero. This scale is fundamental in physics and provides a consistent framework for understanding thermal energy and its relationship to various physical processes.
  • #1
MatinSAR
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Homework Statement
Prove the equality of ideal gas and thermodynamics temperature for a specific gas.
Relevant Equations
##\dfrac {Q_1}{Q_2}= \dfrac {T_1}{T_2}##
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My first problem is to find the absored and rejected heat. Can I say that it is equal to the work done in an isothermal proccess (##dQ=Pdv##)?

My reasoning : We have ##dQ=C_V d\theta + Pdv##. For constant temperature it becomes :$$dQ=Pdv$$
 
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  • #2
The gas equation of state is expressed as P(v-b) = Rθ, where P is pressure, v is specific volume, b is a constant, R is the gas constant, and θ is temperature in Kelvin. The heat capacity, CV, depends only on temperature θ. To demonstrate θ = T, we use the Carnot cycle. In this cycle, efficiency (η) is given by 1 - Tc/Th, where Tc is the cold reservoir temperature and Th is the hot reservoir temperature.

In a Carnot cycle, efficiency is also expressed as 1 - Qc/Qh. Utilizing the first law of thermodynamics, we substitute Qc = CV(θc - θh) and Qh = CV(θh - θc) into the efficiency equation, solving for θ to find θ = T.
 
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  • #3
connectednatural said:
The gas equation of state is expressed as P(v-b) = Rθ, where P is pressure, v is specific volume, b is a constant, R is the gas constant, and θ is temperature in Kelvin. The heat capacity, CV, depends only on temperature θ. To demonstrate θ = T, we use the Carnot cycle. In this cycle, efficiency (η) is given by 1 - Tc/Th, where Tc is the cold reservoir temperature and Th is the hot reservoir temperature.

In a Carnot cycle, efficiency is also expressed as 1 - Qc/Qh. Utilizing the first law of thermodynamics, we substitute Qc = CV(θc - θh) and Qh = CV(θh - θc) into the efficiency equation, solving for θ to find θ = T.
This is another method to solve. Thanks for your reply ...
What's your idea about what I've said?
Can I say that the absored or rejected heat is equal to the work done in an isothermal proccess (##dQ=Pdv##)? Because we have ##dQ=C_V d\theta + Pdv##. For constant temperature it becomes :$$dQ=Pdv$$
 

FAQ: Question about the thermodynamic temperature scale

What is the thermodynamic temperature scale?

The thermodynamic temperature scale is an absolute scale for measuring temperature based on the laws of thermodynamics. The Kelvin (K) is the unit of measurement in this scale, and it starts at absolute zero, the point at which all thermal motion ceases.

Why is the Kelvin scale used in scientific measurements?

The Kelvin scale is used in scientific measurements because it is an absolute scale with a true zero point (absolute zero), which simplifies the equations and calculations in thermodynamics and other scientific fields. It also allows for consistent and reproducible measurements across different experiments and studies.

What is absolute zero?

Absolute zero is the lowest possible temperature, theoretically the point at which all molecular motion stops. It is defined as 0 Kelvin, which is equivalent to -273.15 degrees Celsius or -459.67 degrees Fahrenheit. At absolute zero, a system has minimal thermal energy.

How is the Kelvin scale related to the Celsius scale?

The Kelvin scale is directly related to the Celsius scale. The two scales have the same size degree, but they start at different points. The conversion formula is K = °C + 273.15. This means that to convert a temperature from Celsius to Kelvin, you simply add 273.15 to the Celsius temperature.

What are practical applications of the thermodynamic temperature scale?

The thermodynamic temperature scale is used in a wide range of scientific and engineering applications, including physics, chemistry, and astronomy. It is essential for understanding and calculating the behavior of gases, the efficiency of engines, the properties of materials at different temperatures, and various other phenomena in thermodynamics and statistical mechanics.

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