Category Archives: thermodynamics

Sun day in the Park with Gibbs; or, I have no life and it’s all CarnotCycle’s fault

There are many data tables out there, that are unfortunately not transcribed into usable form, but are stuck as images that cannot be searched. A thermodynamical blog, CarnotCycle, has provided some of these here.

Having no entertainments of any lasting value, I’ve decided to transcribe that one into a common format, Microsoft Excel (2007+ file format). They are here: CarnotCycle-Thermodata.

Although he claims they are in SI, they aren’t. SI does not use the calorie as a unit of energy, instead using the joule. Similarly with degree centigrade and kelvin. I have added a tab to convert the semi-SI to full SI. Digit significance has been maintained while doing this.

I do not know what book he got them out of, so I have to request you cite them as coming from his blog, for now. If you want to credit me with the transcription, that is fine. Use your preferred/recommended/required citation style to do this.

Some notes:

  • Some values were given in parenthesis. In Excel, parentheses are used to indicate a negative number in accounting. I changed this format to gray background with center-aligned numbers.
  • One value was given with a question mark. This is marked with a red background.
  • One value is suspiciously positive, I have marked this with a yellow background.
  • Where needed, scientific notation is use to maintain the correct number of significant digits.
Advertisements

I wish this was a real unit of measure

I had to take two semesters of thermodynamics to get my undergraduate degree. The textbook we used in that class was not very good. Even the professor of one of the sections admitted that. Besides the “you have to know it to learn it” problem, there were a few more entertaining errors, as the following picture shows:

Badthermounits
(Click to see it full size)

You probably immediately noticed them because they were circled in pencil. First off, the line describing density is completely scrambled. I suspect something got pasted into the wrong column during the editing process. How this lead to units of kg/m instead of kg/m3 I don’t have an idea of.

Secondly, a unit of pressure called the “millimeter of energy” is defined below. Wouldn’t it be awesome if there was such a thing, and that you could measure the energy of a substance with a ruler, the way we can measure pressure? No more steam tables or relative reference states! Everything could be absolutely quantified with a ruler! I may have to turn this into a story somehow, I just need a plot.

Two last things: the correct unit is “millimeter of mercury” (760 mm Hg is equal to a standard atmosphere of pressure) and this textbook partially inspired the authoring of another thermo textbook with the goal of being better than this one.