R Constant
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R Constant
What is the R constant in PV=nRT, I keep hearing there are different R constant and I am confused about that?
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Re: R Constant
The R constant is the universal gas constant, and the reason there are different values for it is because the units can vary, from atmospheres to barrs.
Re: R Constant
Alexis Robles 2k wrote:What is the R constant in PV=nRT, I keep hearing there are different R constant and I am confused about that?
Hello,
For the Ideal Gas Law (PV=nRT), R= 8.314J/molK, which is the universal gas constant. I believe there is also differing R constants depending on units used. I found the section "The Gas Constant (R)" on this website to be helpful!
https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law
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Re: R Constant
The R constant will be provided on the "Constants and Formulas" worksheet which can be found on the 14B class website and will be provided on tests and midterms, so we will not have to remember it. The constant can change depending on what units it is in, but different unit forms are also provided on the formula sheet.
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Re: R Constant
There are different R constants that have different units so you just pick the R constant that has units matching the other parts (i.e. atm or bar)
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Re: R Constant
The R constant differs depending on what units are used for pressure so we don't have to manually convert it
Re: R Constant
There are different values for the constant R but that is only because it depends on the units that are being used, but they will be provided on the equation sheet that is given on the tests.
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Re: R Constant
R is the gas constant. It has different values depending on what units you are using.
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Re: R Constant
There are different values for R depending on the units that you are using in your calculations
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Re: R Constant
R constants are given and should be applied based on the units given in the problem. Pressure is the unit to look for as it determines which R constant to plug ig to PV = nRT
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Re: R Constant
The R constant is the gas constant. Its value is determined by the units in the specific problem.
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Re: R Constant
The R constant is given on the sheet of constants and equations for the test, so you will not need to memorize it( but familiarize yourself with it).
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Re: R Constant
In many of our examples and homework problems, the R constant is 8.314 J/mol·K, but if you look at Dr. Lavelle's constants and equations sheet, R is the gas constant and actually has different values. The R value you use depends on the units that are given in the problem.
Re: R Constant
8.314 J/mol·K is the most common used form for the R gas constant, but there are other types of numbers given for it depending on the units. I would suggest memorizing this number just in case the formula sheet has a different value on it since this is the most common used form of it used in our problems
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Re: R Constant
Correct, there are 3 different R values depending on the units that are presented to you, such as atm or torr. But they all are equivalent to each other (even though their units are somewhat different(.
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