Week #5: (10/8) Ideal Gas Law.

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rjagodowski
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Joined: Fri Sep 04, 2015 6:59 pm

Week #5: (10/8) Ideal Gas Law.

Post by rjagodowski »

Last week we discussed Boyle's Law for gases, this week we will use that as a springboard to the Ideal Gas Law. Here's a link about Boyle's Law from Wikipedia to get us started.

The Ideal Gas Law from:
Wikipedia

ChemWiki

The Ideal Gas Law requires that all units be in absolute measurements, meaning that they must be greater than or equal to zero. No negative numbers. For temperature scales, both the common Fahrenheit and Celsius scales have negative temperatures, so they cannot be used in Ideal Gas Law calculations. Instead, the Rankine and Kelvin scales are used. Both of these have 0 degrees as "absolute zero", the temperature at which all atomic/molecular motion has stopped. The Rankine scale then defines one degree Rankine as equal to one degree Fahrenheit. The Kelvin scale defines one degree Kelvin as equal to one degree Celsius.

Likewise, pressures must be measured using an absolute scale. So all pressures must be measured such that a perfect vacuum is 0 and any additional atoms/molecules added will create a positive pressure.

A link explaining the Rankine Temperature Scale. This is an "absolute" scale where the lowest temperature is 0 degrees (known as absolute zero).

Here's a chart showing common temperatures measured in the different scales: Kelvin, Rankine, Fahrenheit, Celsius.
Temperature Conversion Charts.jpg
Temperature Conversion Charts.jpg (83.06 KiB) Viewed 2025 times
Here's a link to a Demonstration of the Ideal Gas Law. NOTE: This demo uses Java, so if you are concerned about running Java apps on your computer, run this simulation on somebody else's computer! :)




In relation to this will be a discussion of CFM and SCFM in terms of pneumatic air flow. This allows a manufacturer to publish a standardized flow-rate related to a specific temperature and pressure.

SCFM vs. CFM from eHow.com .
eebergstrom

Re: Week #5: (10/8) Ideal Gas Law.

Post by eebergstrom »

got it.
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