Here are some useful physical constants, conversion factors, and unit prefixes. They are used in many calculations in chemistry, as well as in physics and other sciences.
Useful Constants
Acceleration of Gravity | 9.806 m/s2 |
Avogadro’s Number | 6.022 x 1023 |
Electronic Charge | 1.602 x 10-19 C |
Faraday Constant | 9.6485 x 104 J/V |
Gas Constant | 0.08206 L·atm/(mol·K)
8.314 J/(mol·K) 8.314 x 107 g·cm2/(s2·mol·K) |
Planck’s Constant | 6.626 x 10-34 J·s |
Speed of Light | 2.998 x 108 m/s |
p | 3.14159 |
e | 2.718 |
ln x | 2.3026 log x |
2.3026 R | 19.14 J/(mol·K) |
2.3026 RT (at 25°C) | 5.708 kJ/mol |
Common Conversion Factors
Quantity | SI Unit | Other Unit | Conversion Factor |
---|---|---|---|
Energy | joule | calorie erg | 1 cal = 4.184 J 1 erg = 10-7 J |
Force | newton | dyne | 1 dyn = 10-5 N |
Length | metre | Angstrom | 1 Å = 10-10 m = 10-8 cm = 10-1 nm |
Mass | kilogram | pound | 1 lb = 0.453592 kg |
Pressure | pascal | bar atmosphere mm Hg lb/in2 | 1 bar = 105 Pa 1 atm = 1.01325 x 105 Pa 1 mm Hg = 133.322 Pa 1 lb/in2 = 6894.8 Pa |
Temperature | kelvin | Celsius Fahrenheit | 1°C = 1 K 1°F = 5/9 K |
Volume | cubic metre | litre gallon (U.S.) gallon (U.K.) cubic inch | 1 L = 1 dm3 = 10-3 m3 1 gal (U.S.) = 3.7854 x 10-3 m3 1 gal (U.K.) = 4.5641 x 10-3 m3 1 in3 = 1.6387 x 10-6 m3 |
SI Unit Prefixes
Factors | Prefix | Symbol |
---|---|---|
1012 | tera | T |
199 | giga | G |
106 | mega | M |
103 | kilo | k |
102 | hecto | h |
101 | deca | da |
10-1 | deci | d |
10-2 | centi | c |
10-3 | milli | m |
10-6 | micro | µ |
10-9 | nano | n |
10-12 | pico | p |
10-15 | femto | f |
10-18 | atto | a |