How Keen Is Your Rank? Reference Page

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Purpose of How Keen Is Your Rank?

Temperature is the most common measured and reported quantity in in chemical processes. The concept of temperature is fundamental to modeling, designing, and monitoring chemical processes. The videos present the four common temperature scales, Kelvin, Celsius, Fahrenheit, and Rankine, and how to convert temperatures and temperature intervals among the four of them. The title is a pun on the name of the least well known of the four scales, the Rankine. The Wikipedia article on Rankine will provide you with much more information than you wanted to know.

The Full Story Video

The Full Story Video examines common conceptions and misconceptions about temperatures and temperature intervals, compares the four scales, shows how to derive the conversions, lists the conversions, and then has two examples of their use. It is recommended for those who have not been exposed to temperature before or who have struggled with understanding what temperature is or how it is used.

Video Link Goes Here Visuals, Transcript, Conversion Table

The Just The Facts Video

The Just The Facts Video explains the difference between temperature and temperature interval, presents the conversions among the four scales for both temperature and temperature intervals, and then has two examples of applying the conversions. It is recommended for those who have a reasonably good understanding of pressure and are just looking for a refresher or a review.

Visuals, Transcript, Conversion Table

Conversion Tables

Temperatures

Convert From \(\rightarrow\) Kelvin (\(\mathrm{K}\)) Celsius (\(\mathrm{^\circ C}\)) Fahrenheit (\(\mathrm{^\circ F}\)) Rankine (\(\mathrm{^\circ R}\))
TO \(\downarrow\)
\(\mathrm{K}\) N/A \(T(\mathrm{K}) = T(\mathrm{^\circ C}) + 273.15\) \(T(\mathrm{K}) = \frac{5}{9} [T(\mathrm{^\circ F}) - 32] + 273.15\) \(T(\mathrm{K}) = \frac{5}{9} T(\mathrm{^\circ R})\)
\(\mathrm{^\circ C}\) \(T(\mathrm{^\circ C}) = T(\mathrm{K}) - 273.15\) N/A \(T(\mathrm{^\circ C}) = \frac{5}{9}[T(\mathrm{^\circ F}) - 32]\) \(T(\mathrm{^\circ C}) = \frac{5}{9}[T(\mathrm{^\circ R}) - 491.67]\)
\(\mathrm{^\circ F}\) \(T(\mathrm{^\circ F}) = \frac{9}{5} T(\mathrm{K}) - 459.67\) \(T(\mathrm{^\circ F}) = \frac{9}{5} T(\mathrm{^\circ C}) + 32\) N/A \(T(\mathrm{^\circ F}) = T(\mathrm{^\circ R}) - 459.67\)
\(\mathrm{^\circ R}\) \(T(\mathrm{^\circ R}) = \frac{9}{5} T(\mathrm{K})\) \(T(\mathrm{^\circ R}) = \frac{9}{5} T(\mathrm{^\circ C}) + 491.67\) $\(T(\mathrm{^\circ R}) = T(\mathrm{^\circ F}) + 459.67\) N/A

Temperature Intervals

Convert From \(\rightarrow\) \(\Delta T\) Kelvin (\(\mathrm{K}\)) \(\Delta T\) Celsius (\(\mathrm{^\circ C}\)) \(\Delta T\) Fahrenheit (\(\mathrm{^\circ F}\)) \(\Delta T\) Rankine (\(\mathrm{^\circ R}\))
TO \(\downarrow\)
\(\Delta T\ (\mathrm{K})\) N/A equal \(\Delta T(\mathrm{K}) = \frac{5}{9} \Delta T(\mathrm{^\circ F})\) \(\Delta T(\mathrm{K}) = \frac{5}{9} \Delta T(\mathrm{^\circ R})\)
\(\Delta T\ (\mathrm{^\circ C})\) equal N/A \(\Delta T(\mathrm{^\circ C}) = \frac{5}{9} \Delta T(\mathrm{^\circ F})\) \(\Delta T(\mathrm{^\circ C}) = \frac{5}{9} \Delta T(\mathrm{^\circ R})\)
\(\Delta T\ (\mathrm{^\circ F})\) \(\Delta T(\mathrm{^\circ F}) = \frac{9}{5} \Delta T(\mathrm{K})\) \(\Delta T(\mathrm{^\circ F}) = \frac{9}{5} \Delta T(\mathrm{^\circ C})\) N/A equal
\(\Delta T\ (\mathrm{^\circ R})\) \(\Delta T(\mathrm{^\circ R}) = \frac{9}{5} \Delta T(\mathrm{K})\) \(\Delta T(\mathrm{^\circ R}) = \frac{9}{5} \Delta T(\mathrm{^\circ C})\) equal N/A

Definitions

Temperature
A measure of the average kinetic energy of the colliding and/or vibrating atoms in a system.
Absolute Zero
The lowest limit of the thermodynamic temperature scale. Determined by extrapolating the ideal gas law. Colloquially known as the lowest possible temperature.
Absolute Temperature Scale
A temperature scale that begins at absolute zero.
Kelvin
The SI absolute temperature scale. Named after Lord Kelvin, a British mathematisian and engineer.
Celsius
The SI common temperature scale. Named after Anders Celsius, a Swedish astronomer.
Fahrenheit
The American Engineering common temperature scale. Named after Daniel Gabriel Fahrenheit, a physicist born in Poland.
Rankine
The American Engineering absolute temperature scale. Named after William John Macquorn Rankine, a Scottish methematician and physicist.
Ideal Gas Law
For gas-phase components, and low enough pressures and high enough temperatures, the relationship among absolute temperature, \(T\), absolute pressure, \(P\), total volume, \(V\), and number of moles, \(n\). The relationship is usually written as \(PV=nRT\), where \(R\) is the universal gas constant. It can also be written as \(P\hat{V}=RT\), where \(\hat{V}=V/n\) is the molar volume.
Heat Capacity
The change in internal energy required to change the temperature of a specified amount of a substance by one degree in a specified temperature scale. The two most common ones are at constant pressure, \(C_P\), and a constant volume, \(C_V\).