Summary Response
1. Strong Acids and Bases
A strong acid/base is one which is fully/wholly/completely dissociated / ionized into many free H+ /OH- ions i.e.H+ ions than molecules. e.g.
HCl(aq) → H+ (aq) + Cl- (aq) 3 (aq) → H+ (aq) + NO3 - (aq)
Strong bases/alkalis exists more as free
OH- ions than molecules. e.g.
KOH(aq) → K+ (aq) + OH- (aq) (aq) → Na+ (aq) + OH- (aq)
Strong acids have pH 1/2/3
Strong alkalis/bases have pH 12/13/14 while weak bases/alkalis have pH 11/10 /9 / 8
2. Weak Acids and Bases
A weak base/acid is one which is partially /partly dissociated /ionized in water into free OH- (aq) and H+ (aq) ions.
Weak acids exists more as molecules than as free H+ ions. e.g.
CH3 COOH(aq) → H+ (aq) + CH3 COO- (aq) 2 CO2 (aq) → H+ (aq) + CO3 2- (aq)
Weak bases/alkalis exists more as molecules than free OH- ions. e.g.
NH4 OH(aq) → NH4 + (aq) + OH- (aq) 2 (aq) → Ca2+ (aq) + 2OH- (aq)
pH Properties of Acids and Bases
The concentration of an acid/base/alkali is based on the number of moles of acid/bases dissolved in a decimeter(litre)of the solution.
An acid/base/alkali with more acid/base/alkali in a decimeter(litre) of solution is said to be concentrated while that with less is said to be dilute.
Weak acids have high pH 4/5/6 while weak bases/alkalis have pH 11/10/9/8.
pH is a measure of H
+ (aq) concentration in a solution.
The higher the H
+ (aq) ions concentration;
The higher the acidity
The lower the pH
The lower the concentration of OH-(aq)
The lower the alkalinity
