PREFIX for SI UNITS
- 10‾15 femto (f), 10‾12 pico (p), 10‾9 nino (n), 10‾6 micro (m);
- 10‾3 milli (m), 10‾2 centi (c), 10‾1 deci (d);
- 103 kilo (k), 106 mega, and 109 giga (g).
LENGTH
The SI unit for length is meter.
1 meter is equal to: 10‾� milli (m), 10‾� centi (c), and 10‾� deci (d). So;
1000 cm� = 10� (10‾� m)� = 103 X 10‾6 = 10‾� m�
1 L (litre) = 1 dm� = 1 (10‾� m)� = 10‾� m�
PRESSURE
There are three different units of pressure used in chemistry: atmospheres (atm), millimeters of mercury (mmHg or torr), and Pascals (Pa) or, more commonly, kiloPascals (kPa).
1 atm ≈ 760 torr = 1.01325 x 105 Pa = 1.01325 bar
1 Torr = 1mmHg ; 1 bar = 105 Pa ; 1 Pa = 1 Nm‾� = J m‾�.
TEMPERATURE
0�C = 273.15 K
ENERGY
1 calorie = 4.184 Joule
1 wavelength corresponds to 1 ev = 1.2398 x 10‾4 cm
1 electron volt = 1.602 x 10‾�� erg
1 erg = 10‾7 Joule
1 BTU = 1055 Joule
1 kw = 2545 BTU hr‾�
DIPOLE MOMENT
1 D = (1.602 x 10-19 C) x (2.08 x 10-11) = 3.332 x 10-30 C m.FUNDAMENTAL CONSTANTS
- Velocity of light, c = 2.998 x 108 m s‾�
- One electron charge, e = 1.602 x 10-19 C ; C = coulomb
- Mass of one neutron, mn = 1.673 x 10-27 kg
- Mass of one electron, me = 9.109 x 10-31 kg
- Gas constant, R = 8.314 J K‾� mol‾�
- Boltzmann constant, k = 1.381 J K‾�
- Avogadro constant, No = 6.022 x 1023 mol‾�
- Planck constant, h = 6.626 x 10-34 J s
- Gravitional constant, G = 6.672 x 10-11 Nm� kg‾�
- Vacuum permitivity, εo = 8.854 x 10-12 J‾� C‾� m‾�
- Vacuum permeability, μo = 4π J s� C‾� m‾�
