Common Physical and Chemical Constants
Avogadro's Number 6.02217 X 1023  things/mole
Planck's Constant 6.6260755 X 10-34 Js 
1 atmosphere (atm) 101,325 Pascals (Pa)  =  101.325 kPa 
= 760 mm of Hg = 760 Torr = 1.01325 bar 
1 mole of any gas at STP  22.4 L (0oC, 1 atm) 
1 mole of any gas at SATP 24.8 L (25oC, 1 atm) 
Ideal Gas Law Constant (R) 0.0821 L atm mol-1 K-1
= 8.31430 L kPa mol-1 K-1 

= 8.31441 J mol-1 K-1
1 calorie (cal) 4.184 J 
1 Cal 1 kcal = 1000 calories
1 atomic mass unit (amu) 1.6605665 X 10-24
1 tonne(t) 1000 kg = 1 Mg 
Speed of light in a vacuum 299792458 m s-1  (3.0 X 108 m s-1
Rest mass of an electron (me 0.000548712 u  = 9.1093897 X 10-28 g
Rest mass of a proton (mp) 1.00727605 u = 1.67262305 X 10-24 g
Rest mass of a neutron (mn) 1.008665 u  = 1.674954 X 10-24 g
1 kiloWattHour(kWh) 3.6 MJ 
1 Joule (J) 1 kg m2 s-2 = 1.0 X 107 erg 
1 Coulomb(C) 6.24 x 1018 e-
Electronic charge on an electron 1.60217733 X 10-19 C
1 Ampere(A) 1 Coulomb/s 
1 Volt(V) 1 J/C = 96.5 kJ/mole 
1 electron volt (eV) 1.60219 x 10-19
Faraday's Constant 96,486.7 C/mole e-