Constants and Conversions
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Joules = Coulombs⋅Volts = Kilograms⋅meters2seconds2
Power = Current⋅Volts in units Joulesseconds
Keep in mind that there are two systems for using units - the MKS and cgs system. The MKS system uses meters, kilograms, and seconds together. The cgs system uses centimeters, grams, and seconds together
Also keep in mind that there are multiple meanings for R. R, like V, is a commonly used letter for formulas in the physical sciences. It is imperative to keep track of what R you are talking about. For physical chemistry specifically, R can mean four different things.
- Rydberg constant, R. Seen in E=−R1n2
- Radial function, R. Seen in ψ=RnℓYmℓ
- Bond length R. Seen in the moment of inertia formula for a rigid rotor I=μ R2
- Constant R. Seen in the ideal gas law PV=nRT
joule | kJmol | eV | Eh | cm−1 | Hz | |
---|---|---|---|---|---|---|
1joule | 1 | 6.022x1020 | 6.241x1018 | 2.294x1017 | 5.034x1022 | 1.509x1033 |
1kJmol | 1.660x10−21 | 1 | 1.036x10−2 | 3.809x10−4 | 83.596 | 2.506x1012 |
1eV | 1.602x10−19 | 96.485 | 1 | 3.675x10−2 | 8065.54 | 2.418x1014 |
1Eh | 4.359x10−18 | 2625.500 | 27.211 | 1 | 2.1947x105 | 6.580x1015 |
1cm−1 | 1.986x10−23 | 1.196x10−2 | 1.239x10−4 | 4.556x10−6 | 1 | 2.998x1010 |
1Hz | 6.626x10−34 | 3.990x10−13 | 4.135x10−15 | 1.159x10−16 | 3.336x10−11 | 1 |
Constant | Symbol | Value |
---|---|---|
Atomic mass constant | mu | 1.6605402x10−27kg |
Avogadro constant | NA | 6.0221367x1023mol−1 |
Bohr magneton | βB = eℏ2me | 9.2740154x10−24J⋅ T−1 |
Bohr radius | a0 = 4πϵ0mee2 | 5.29177249x10−11m |
Boltzmann constant | kB | 1.380658x10−23J⋅ K−1 |
.695038cm−1 | ||
Electron rest mass | me | 9.1093897x10−31kg |
Gravitational constant | G | 6.67259x10−11m3⋅ kg−1⋅ s−2 |
Molar gas constant | R | 8.314510J⋅ K−1⋅ mol−1 |
.0831451dm3⋅ bar⋅ K−1⋅ mol−1 |
||
.0820578dm3⋅ atm⋅ K−1⋅ mol−1 | ||
Molar volume, ideal gas, one bar, 0∘C | - | 22.71108L⋅ mol−1 |
Molar volume, ideal gas, one atm, 0∘C | - | 22.41409L⋅ mol−1 |
Nuclear magneton | μn = eℏ2mp | 5.0507866x10−27J⋅ T−1 |
Permittivity of vacuum | ϵ0 | 8.854187816x10−12C2⋅ J−1⋅ m−1 |
4πϵ0 | 1.112650056x10−10C2⋅ J−1⋅ m−1 | |
Planck constant | h | 6.6260755x10−34J⋅ s |
ℏ | 1.05457266x10−34J⋅ s | |
Proton charge | e | 1.60217733x10−19C |
Proton magnetogyric ratio | γp | 2.67522128x108s−1⋅ T−1 |
Proton rest mass | mp | 1.6726231x10−27kg |
Rydberg constant (Bohr) | R∞ = mee48ϵ20h2 | 2.1798736x10−18J |
109737.31534cm−1 | ||
Rydberg constant (experimental) | Rh | 109677.581cm−1 |
Speed of light in vacuum |
c |
299792458m⋅ s−1 |