The gas constant, represented by the symbol R, is a significant constant in physics. It's a unit of energy per temperature increment per mole, also referred to as the ideal gas constant, molar gas constant, or universal gas constant. It's equivalent to the Boltzmann constant but is expressed differently, as the pressure-volume product.
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In the realm of physics, the gas constant is the constant of proportionality that connects the energy scale to the temperature scale when considering one mole of particles at a defined temperature. The ideal gas constant is essentially a combination of Boyle’s law, Avogadro’s number, Charles’s law, and Gay-Lussac’s law. Hence, the gas constant R is given by –
Gas constant R = 8.3144598(48) J⋅mol−1⋅K−1
The numbers in parentheses denote the uncertainty in the measurement of the gas constant value.
The gas constant is used inversely in a variety of disciplines, which is why it's expressed in multiple units. Below are some values of the gas constant in different units-
| Gas Constant Value | Units |
| 8.3144598(48) | J⋅K−1⋅mol−1 |
| 8.3144598(48)×103 | amu.m2.s-2.K-1 |
| 8.3144598(48)×10−2 | L.bar.K-1.mol-1 |
| 8.3144598(48) | m3.Pa.K-1.mol-1 |
| 62.363577(36) | L.Torr.K-1.mol-1 |
| 1.9872036(11)×10−3 | kcal.K-1.mol-1 |
| 8.2057338(47)×10−5 | m3.atm.K-1.mol-1 |
| 0.082057338(47) | L.atm.K-1.mol-1 |
According to the US Standard Atmosphere, the R constant for atm is defined as
R = 8.31432×103 N⋅m⋅kmol−1⋅K−1.
The specific gas constant is the ratio of the molar gas constant (R) to the molar mass (M) of the gas mixture. It is represented by Rspecific and mathematically expressed as –
The gas constant R can be expressed using the ideal gas equation PV = nRT as-
Where,
Thus, by writing pressure as force per unit area, we can derive the dimensional expression for R as-
Area and Volume can be expressed in terms of length as volume=(length)3 and area = (length)2
Thus, we get-
Since force times length is work, we get-
Thus, the gas constant can be interpreted as work per degree per mole.
We hope that you now have a better understanding of the gas constant, its value in different units, the ideal gas formula, and its application in physics.
Related Topics in Physics:
| Stefan-Boltzmann Constant |
| Faraday Constant |
| Value of Gravitational Constant |
| Rydberg Constant |
What is the formula to calculate the specific gas constant?
Specific gas constant is given by the formula: R_specific = R/M
What is the value of Gas constant (R)?
The value of Gas constant is R = 8.3144598(48) J⋅mol−1⋅K−1
Write the formula for an ideal gas equation.
The ideal gas equation is given by PV=nRT.
What is a gas constant also known as?
Gas constant is also known as ideal gas constant or molar gas constant or universal gas constant.
The ideal gas constant is the combination of which laws?
The ideal gas constant is the combination of: Boyle’s law, Charles’s Law, Gay-Lussac’s law, Avogadro’s number