Core
Reactions: Acid-base
Slide 13 of 42
Stength and
concentration of ions
HB(s l or g) H+(aq) + B–(aq)
Partial dissociation means that if 1 mol of the acid is dissolved in
water, some molecules of HB will remain intact, and so less
than 1 mol each of H+(aq) and B–(aq) ions result (see previous slide).
Another
way of putting it is to say that a 1M solution of strong acid such HCl will
produce a solution that is 1molar in concentration of both H+ and Cl– ions.
But
1M solution of ethanoic acid (CH3COOH) will contain some undissociated (unionized)
CH3COOH
molecules, and therefore will be less than 1 mol dm–3 of each of H+ and CH3COO– (ethanoate) ions.