How to Convert Ideal Gas Constants from Mass-Based Units to Molar-Based Units?

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Discussion Overview

The discussion revolves around the conversion of ideal gas constants from mass-based units (kJ/(kg*K)) to molar-based units (kJ/(kmol*K)). Participants explore the necessary steps and resources required for this conversion, particularly focusing on the availability of molecular mass data.

Discussion Character

  • Homework-related

Main Points Raised

  • One participant initially expresses confusion about how to perform the conversion without access to a periodic table, which is not included in the provided text.
  • Another participant suggests that the original poster could easily find a periodic table online.
  • The original poster clarifies that while they have access to chemistry books, the problem specifically requires using data from the text, which lacks a periodic table.
  • The original poster later finds a table within the text that lists molecular masses, indicating that the problem is now more straightforward.
  • The original poster questions why a periodic table was not included in the thermodynamics book, expressing frustration over this omission.

Areas of Agreement / Disagreement

The discussion reflects a progression from confusion to resolution for the original poster, but there is no explicit consensus on the necessity of including a periodic table in the text. The initial disagreement about resource availability is resolved as the original poster finds the needed information.

Contextual Notes

The discussion highlights limitations regarding the availability of certain reference materials within the text, which may affect the ability to perform conversions without external resources.

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[SOLVED] Ideal gas unit conversions

Homework Statement



The ideal gas constants used in this text are typically mass-based: kJ / (kg*K). It is more useful to have them in units of kJ / (kmol*K). How to convert them using data from this text?

Homework Equations





The Attempt at a Solution



I'd think that this is a problem in which I'd consult the periodic table to obtain the molecular mass of a given compound, but the P. table is not included. I have steam tables, gas-constant/critical point properties tables, etc. Seems like such a simple question, yet I'm not seeing the path. Can anyone point me in the right direction?
 
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You have a computer. Surely you can find a periodic table somewhere on the internet.
 
Yes, obviously. I also have numerous chemistry books. But the problem specifically states to use data contained within the text--there is no periodic table within. Hence, my confusion.

Converting grams to moles is trivial with a PT. Without the PT; I don't understand...
 
Nevermind, I found a table in the text that lists molecular masses of some selected compounds. The problem is reduced to triviality, afterall.

Wouldn't it be much simpler to just include a PT on the frontsheet or at least appendix, like every other science book I've encountered? What kind of Thermodynamics book wouldn't include one? Silly!

Cheers
 

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