Answer: An Acid is a substance that can donate H+ ion.
Step-by-step explanation:
An Acid is any substance that can donate hydrogen ion and form covalent bond with electron pair. When an acid is dissolved in water, there is a shifted balance between the hydrogen ion and hydroxide ion leading to more hydrogen ion in water,which the the solution acidic. There are two classification of Acids, they are weak and strong acid.
A strong acid dissociate completely in aqueous solution, examples are Hydrochloric acid, tetraoxosulphate6 acid(HCl and H2S04) e.t.c
Weak acid don't dissociate in aqueous solution completely, examples include citric acid, oxalic acid, carbonic acid e.t.c