ideal gas constant
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ideal gas constant
what is the R value for PV=nRT that we are using in order to solve for partial pressure or concentration (n/V) ?
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Re: ideal gas constant
On the 14B website, there's a link to a Constants and Equations PDF that essentially has everything we would need to know for the class. From there, you can see that the R value (Gas constant) is 8.314 J·K^-1·mol^-1 or 8.206 x 10^2 L·atm·K^-1·mol^-1 or 8.314 x 10^2 L·bar·K^-1·mol^-1 or 62.364 L·Torr·K^-1·mol^-1.
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Re: ideal gas constant
Also, there is an example (51.3 on pg.419) in the seventh edition of the textbook that uses 8.3145*10^-2 L*bar*K^-1*mol^-1 as R to find the partial pressure of the reactant. They use moles, liters, and kelvin for the other units.
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Re: ideal gas constant
I believe one of the most commonly used values for the R constant is 8.206 x 10-2 L·atm/K·mol, but it is important to keep in mind that this value can change depending on which units are being used as shown in the previous answers. Also, my TA mentioned that this constant will be provided for us on exams so we do not need to memorize it, but that we should know the most commonly used unit conversions (i.e. mL to L, bar to atm, etc.) in order to make sure that all of the units cancel out in the end.
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Re: ideal gas constant
The value of R used is dependent upon the unit of pressure used.
For example if atmosphere is the unit of pressure used then 0.08206 is the R value. However, if torr is the unit of pressure used then use the R value of 62.36.
For example if atmosphere is the unit of pressure used then 0.08206 is the R value. However, if torr is the unit of pressure used then use the R value of 62.36.
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