Units and Nomenclature

 

Symbol

Meaning

Usual units

Reference

a

transfer coefficient

none

122(b)

F

Faraday constant (96.485 kC mol-1)

F = eNA

C

121

h

overpotential

(difference in potential between surface states and electrolyte)

 

h = E - Eeq where

    E = potential of electrode vs. a reference

    Eeq = equilibrium potential of electrode

V

122(b)

R

gas constant (8.31451 J mol-1 K-1)

J mol-1 K-1

121

T

absolute temperature

K

 

e

elementary charge (1.602177 ´ 10-19 C)

C

121

NA

Avagadro constant (6.02214 x 1023 mol-1)

mol-1

121

k

Boltzmann constant (1.38066 ´ 10-23 J K-1)

J K-1

121

c

speed of light (2.99792458 ´ 108 m s-1)

m s-1

121

h

Planck constant (6.62608 ´ 10-34 J s)

J s

121

 

Temperatures are quoted on the Celsius scale.

Conversion between kelvin and degrees celsius: qC        / °C = T / K – 273.150

 

A number of common units of pressure are used

1 atmosphere (atm)      = 760 Torr
                                    = 760 millimetres of mercury (mmHg) at 0 °C
                                    = 1.01325 ´ 105 pascals (Pa)

                                    = 1.01325 ´ 105 newtons per square metre (N m-2)

                                    = 1.01325 bar

                                    = 14.6959 pounds per square inch (psi or lb/in2)

 

The conventional English spelling of sulphur and its derivatives (sulphate, sulphuric, etc.) is used in preference to the current IUPAC standard (sulfur).

 

The common names acetone and IPA (isopropyl alcohol) are used in preference to the systematic names propanone and 1-propanol.

 

The old naming standard for groups of elements has been used as this is the standard commonly used in semiconductor studies. Group IV corresponds to group 14.

 

 

Abbreviations used:

 

Abbreviation

Description

 

s.c.c.m.

 

standard cm3 per minute  (quantity of gas equivalent to 1 cm3 at standard temperature and pressure)

 

p.p.m.

 

parts per million

 

 

Non standard units:

 

Symbol

Units

hr / hrs

hour / hours

min / mins

minute / minutes

eV

electron volts  (1 eV = the energy acquired by an electron accelerated through a 1 V electric field)

keV

kilo electron volts (1000 eV)

MeV

mega electron volts (1000 keV)

dalton

one twelfth of the mass of a carbon-12 nucleus

inches (1” » 2.54 cm)