Physical Chemistry Essentials - Hofmann A. 2018

Physico-chemical Data and Resources
1.3 Units and Constants

1.3.1 Decimal Factors

Table 1.2

Decimal factors

Factor

Prefix

Symbol

Factor

Prefix

Symbol

10−1

deci

d

10

deka

da

10−2

centi

c

102

hekto

h

10−3

milli

m

103

kilo

k

10−6

micro

m

106

mega

M

10−9

nano

n

109

giga

G

10−12

pico

p

1012

tera

T

10−15

femto

f

1015

peta

P

10−18

atto

a

1018

exa

E

1.3.2 The Greek Alphabet

Table 1.3

The Greek alphabet

Α, α

alpha

Ι, ι

iota

Σ, σ

sigma

Β, β

beta

Κ, κ

kappa

Τ, τ

tau

Γ, γ

gamma

Λ, λ

lambda

Y, υ

upsilon

Δ, δ

delta

Μ, μ

mu

Φ, ϕ

phi

Ε, ε

epsilon

Ν, ν

nu

Χ, χ

chi

Ζ, ζ

zeta

Ξ, ξ

xi

Ψ, ψ

psi

Η, η

eta

Π, π

pi

Ω, ω

omega

Θ, θ

theta

Ρ, ρ

rho

1.3.3 SI Base Parameters and Units

Table 1.4

SI base parameters and units

Symbol

Parameter

Unit

Name

I

Electric current

1 A

ampere

I v

Light intensity

1 cd

candela

l

Length

1 m

metre

m

Mass

1 kg

kilogram

n

Molar amount

1 mol

mole

t

Time

1 s

second

T

Temperature

1 K

kelvin

1.3.4 Important Physico-chemical Parameters and Units

Table 1.5

Important physico-chemical parameters and units

Symbol

Parameter

Unit

Name

b

Molality

1 mol kg−1

B

Magnetic induction

1 T = 1 kg s−2 A−1 = 1 V s m−2

tesla

c

Molar concentration

1 mol l−1

C

Electric capacitance

1 F = 1 kg−1 m−2 s4 A2 = 1 A s V−1

farad

E

Energy

1 J = 1 kg m2 s−2 = 1 C V

joule

ε

Molar extinction coefficient

1 l mol−1 cm−1

ε

Permittivity

1 F m−1

F

Force

1 N = 1 kg m s−2 = 1 J m−1

newton

F

Magnetic flux

1 Wb = 1 kg m2 s−2 A−1 = 1 V s

weber

G

Electric conductance

1 S = 1 kg−1 m−2 s3 A2 = 1 Ω−1

siemens

H

Enthalpy

1 J = 1 kg m2 s−2

joule

η

Viscosity

1 P = 0.1 kg m−1 s−1 = 0.1 Pa s

poise

i

Current density

1 A m−2

j

Flux density

1 mol m−2 s−1

κ

Conductivity

1 S m−2

L

Magnetic inductivity

1 H = 1 kg m2 s−2 A−2 = 1 V A−1 s

henry

Λm

Molar conductivity

1 S m2 mol−1

M

Molar mass1

1 g mol−1 = 1 Da

(dalton)

μ

Electric dipole moment

1 D = 3.336·10−30 C m

debye

ν

Frequency

1 Hz = 1 s−1

hertz

p

Pressure

1 Pa = 1 kg m−1 s−2 = 1 N m−2

pascal

P

Power

1 W = 1 kg m2 s−3 = 1 J s−1

watt

Q

Electric charge

1 C = 1 A s

coulomb

ρ

Density

1 g cm−3

ρ*

Mass concentration

1 mg ml−1

R

Electric resistance

1 Ω = 1 kg m2 s−3 A−2 = 1 V A−1

ohm

S

Entropy

1 J K−1

θ

Temperature

1 °C

degree Celsius

u

Ion mobility

1 m2 s−1 V−1

U, ϕ, E

Electric potential (voltage)

1 V = 1 kg m2 s−3 A−1 = 1 J A−1 s−1

volt

V

Volume

1 l = 1 dm3

V m

Molar volume

1 l mol−1

v

Partial specific volume

1 ml g−1

w

Mass fraction

Volume fraction

1 (typically given in %w/w, %w/v or %v/v)

x

Mole fraction

1

z

Charge number

1

1Note that the molecular mass is the mass of one molecule given in atomic mass units (u, Da). The molar mass is the mass of 1 mol of molecules and thus has the units of g mol−1

1.3.5 Important Physico-chemical Constants

Table 1.6

Important physico-chemical constants

Symbol

Constant

Value

c

Speed of light in vacuo

2.99792458·108 m s−1

e

Elementary charge

1.6021892·10−19 C

ε0 = (μ0·c2)−1

Permittivity in vacuo

8.85418782·10−12 A2 s4 m−3 kg−1

F = e·NA

Faraday’s constant

9.648456·104 C mol−1

g

Earth’s gravity near surface

9.81 m s−2

ge = 2 μe/μB

Landé factor of free electron

2.0023193134

γp

Gyromagnetic ratio of proton

2.6751987·108 s−1 T−1

h

Planck’s constant

6.626176·10−34 J s

kB = R/NA

Boltzmann’s constant

1.380662·10−23 J K−1

me

Mass of electron

9.109534·10−31 kg

mn

Mass of neutron

1.6749543·10−27 kg

mp

Mass of proton

1.6726485·10−27 kg

μ0

Magnetic field constant

4π·10−7 m kg s−2 A−2

μΒ = e·h/(4π·me)

Bohr magneton

9.274078·10−24 J T−1

με

Magnetic moment of electron

9.284832·10−24 J T−1

μΝ = e·h/(4π·mp)

Nuclear magneton

5.050824·10−27 J T−1

NA, L

Avogadro’s (Loschmidt’s) constant

6.022045·1023 mol−1

pø

Standard pressure (IUPAC)

1.00·105 Pa

pnormal

Normal pressure (NIST)

1 atm = 1013.25 hPa

R

Gas constant

8.31441 J K−1 mol−1

R∞

Rydberg’s constant

1.097373177·107 m−1

Tø, θø

Standard temperature (IUPAC)

273.15 K, 0 °C

Tnormal, θnormal

Normal temperature

298.15 K, 25 °C

u

Atomic mass unit

1.6605402·10−27 kg

Vm ø = R·Tø/pø

Molar volume of an ideal gas

22.41383 l mol−1

1.3.6 Conversion Factors

Table 1.7

Conversion factors for energy

J

cal

eV

1 J

1

0.2390

6.24150974·1018

1 cal

4.184

1

2.612·1019

1 eV

1.60217646·10−19

3.829·10−20

1

Table 1.8

Conversion factors for pressure

Pa

bar

atm

mm Hg (Torr)

psi

1 Pa

1

10−5

9.869·10−6

7.501·10−3

1.450·10−4

1 bar

105

1

0.9869

750.1

14.50

1 atm

1.013·105

1.013

1

760.0

14.69

1 mm Hg (Torr)

133.3

1.333·10−3

1.316·10−3

1

1.933·10−2

1 psi

6.895·104

6.897 10−2

6.807 10−2

51.72

1

1.3.7 Thermodynamic Properties of Select Substances

Table 1.9

Enthalpy of formation, Gibbs free energy of formation and molar heat capacity of select substances at normal conditions (Tnormal = 298 K, pnormal = 1.013 bar)

Species

ΔH f in kJ mol−1

ΔG f in kJ mol−1

C p,m in J K−1 mol−1

C(graphite)

0

0

8.53

HCO3 − (aq)

−689.9

−586.8

H2(g)

0

0

28.82

H+ (aq)

0

H2O(l)

−285.83

−237.14

75.4

H2O(g)

−241.83

−228.61

33.58

Ni(OH)2(s)

−444

O2(g)

0

0

29.35

O3(g)

142.67

163.19

39.22

OH− (aq)

−230.02

−157.22