Save
...
4.4 - Chemical changes
4.4.2 - Reactions of acids
5) Strong and weak acids
Save
Share
Learn
Content
Leaderboard
Learn
Created by
Fizza Haider
Visit profile
Cards (9)
Strong acids are completely
ionised
(split up into ions) in
water
Hydrochloric
acid is a strong acid:
HCI
(g) + aq➡ H+(aq) + Cl-(aq)
Ethanoic acid is a weak acid:
CH
,COOH(I) + aq ->
CH ̧COO
̄(aq) + H+(aq)
The pH of a solution is a measure of the
concentration
of
H+
ions.
A pH decrease of one unit indicates that the concentration of
hydrogen
ions has increased by a factor of
10.
For a given concentration of acid, a strong acid will have a higher concentration of
hydrogen
ions and, therefore, a
lower
pH.
The terms
'dilute'
and
'concentrated'
are also applied to acids sometimes.
An acid that has a concentration of
2mol/dm3
is more concentrated than an acid that has a concentration of
0.5mol/dm3.
Strong acids such as hydrochloric acid,
nitric
acid and sulfuric acid are completely ionised in
water.
Weak acids such as
ethanoic
acid, citric acid and carbonic acid are only partially ionised in
water.