What does the Constant R in the Ideal Gas Law mean?

2 Answers

Regnault constant, or Universal Gas Constant.

Explanation:

Gas constant, R, is named after the French chemist Henri Victor Regnault. It is also called the Universal Gas Constant.

Gas constant is equivalent to Boltzmann constant k_B multiplied by Avogadro's number N_A = 6.0221413xx10^23 "things"cdot"mol"^(-1), expressed in terms of energy.

There are many values of R depending on the units used.

Here are some examples:

"8.314 J"cdot"K"^[-1]"mol"^[−1]
8.314xx10^7 "erg"cdot"K"^[−1]"mol"^[−1]
8.314xx10^[−3] "amu" cdot["km"^2]/"s"^2"K"^[−1]
8.314 "L"cdot"kPa"cdot"K"^[−1]"mol"^[−1]
8.314xx10^[−5] "m"^3 "bar"cdot"K"^[−1]"mol"^[−1]
8.314xx10^[−2] "L" "bar"cdot"K"^[−1] "mol"^[−1]"
62.36 "L"cdot"Torr"cdot"K"^[−1]"mol"^[−1]
0.08206 "L"cdot"atm"cdot"K"^[−1]"mol"^[−1]

Jan 20, 2016

R can be viewed as a scaling factor for molar energy of ideal gas law. For ideal gas law, energy can be viewed as increasing linearly with temperature. E=alphaT

Explanation:

Through derivation. it was shown that for one-dimension, E=1/2 RT while for 3 dimension E=3/2 RT
The above is for 1 mole of ideal gas. For 1 molecule of gas, we know that R=N_{A} k
So 1 molecule of ideal gas moving in 3 dimension is E=3/2 kT
You can equate the kinetic energy of the molecule E=1/2 m v^2 to previous equation and get
E=3/2 kT= 1/2 m v^2

Read more
http://homepage.smc.edu/gallogly_ethan/files/ideal%20gas%20law%20derivation.pdf

https://en.wikipedia.org/wiki/KT_(energy)