PP Presentation
Relative Strengths of acids/bases depend on the solvent :
In water: H3O+ is the STRONGEST ACID
OH- is the STRONGEST BASE
Once an acid or base is fully reacted (dissociated) to form these species,
one can no longer distinguish relative strengths. This is called the
LEVELLING ACTION of water
(The relative strengths of two strong acids can only be determined in
non-aqueous solvents)
STRONG ACIDS: HCl, H2SO4, H3PO4, HNO3, HClO4
WEAK ACIDS: CH3CO2H, “H2CO3” (= CO2), HS, HCN, HF
WEAK BASES: NH3, Na2CO3
STRONG BASES: NaOH, Li2O, NaH, Ca(OH)2
Kotz, Table 17.3
In Br rnsted acid-base reactions - H+ transfer occurs from STRONGER to
WEAKER congugate acid-base pair