How do you know which R value to use?
Typically, a higher insulation R rating means better climate control and better energy efficiency for your home. A higher insulation R-value usually means a higher price point as well. For every type and material of insulation, check the R-value per inch of thickness that the manufacturer has listed.
How do you know which R to use in the ideal gas law?
The ideal gas law is: pV = nRT, where n is the number of moles, and R is universal gas constant. The value of R depends on the units involved, but is usually stated with S.I. units as: R = 8.314 J/mol·K. This means that for air, you can use the value R = 287 J/kg·K.
What is the ideal constant R?
The gas constant R is defined as the Avogadro constant NA multiplied by the Boltzmann constant k (or kB):
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Gas constant.
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Gas constant.
| Values of R | Units |
|---|---|
| 8.31446261815324 | kg⋅m2⋅s−2⋅K−1⋅mol−1 |
| 8.31446261815324 (K-12) | L⋅kPa⋅K−1⋅mol−1 |
| Other Common Units | |
| 0.730240507295273 | atm⋅ft3⋅lbmol−1⋅°R−1 |