Helpful Tables and Equations
Uncertainty
uR = √u ....2A + u2B + u2C = RuR √( ) ) ) ....Au A 2 + ( Bu B 2 + ( Cu C 2
Activity
log i =
−0.51 x z x i
2 √μ
1 + (3.3 x α x ) i √μ
or i = 10
−0.51 x z x i
2 √μ
1 + (3.3 x α x ) i √μ
zi = ion charge i =effective diameter of the hydrated ion =solution ionic strength

Ionic Strength
= ΣC z2
1
i i
2 pH = -logaH+=-log(H+[H+]) aH+=10-pH aH+= H+[H+]
pOH = -logaOH-=-log( OH-[OH-]) aOH-=10-pOH aOH-=OH-[OH-]
aH+·aOH-=Kw Kw = 1.00x10-14 at T=25 °C
pH + pOH = 14.00 The [OH-]=[H+]= 1.00x10-7 M in pure water T=25 °C
pKa = -logKa Ka = 10-pKa pKb = -logKb Kb = 10-pKb
Ionic Diameter information
Ion Effective diameter (nm)
H3O+ 0.9
Li+ 0.6
Na+, IO3- , HSO3- , HCO3- , C2H3O2-, H2PO4- 0.45
OH-, F-, SCN-, HS-, ClO3-, ClO4-, MnO4- 0.35
K+, Cl-, Br-, I-, CN-, NO2-, NO3- 0.3
Cs+, Tl+, Ag+, NH4+ 0.25
Mg2+, Be2+ 0.8
Ca2+, Cu2+, Zn2+, Sn2+, Mn2+, Fe2+, Ni2+, Co2+ 0.6
Sr2+, Ba2+, Cd2+, Hg2+, S2- 0.5
Pb2+, CO32-, SO32- 0.45
Hg22+, SO42-, HSO4-, S2O32-, CrO42-, HPO42- 0.40
Al3+, Fe3+, Cr3+ 0.9
PO43-, Fe(CN)63- 0.4
Zr4+, Ce4+, Sn4+ 1.1