Weak acid
(in water)
A substance which partially dissociates in water to give ions H3O+ , e.g. the balanced reaction for ethanoic (acetic) acid:
CH3COOH + H20
CH3COO-
+ H3O+
Strong acid
(in water)
A substance which dissociates quantitatively into H3O+ in water, e.g. hydrochloric acid .
HCl + H20
H3O+ + Cl-