How many items of acid ?

Common acids

Citric Acid

Mineral acids

Solutions of hydrogen halides, such as hydrochloric acid (HCl) and hydrobromic acid (HBr)
Sulfuric acid (H2SO4)
Nitric acid (HNO3)
Phosphoric acid (H3PO4)
Chromic acid (H2CrO4)

Sulfonic acids

Methanesulfonic acid (aka mesylic acid) (MeSO3H)
Ethanesulfonic acid (aka esylic acid) (EtSO3H)
Benzenesulfonic acid (aka besylic acid) (PhSO3H)
Toluenesulfonic acid (aka tosylic acid, or (C6H4(CH3) (SO3H))

Carboxylic acids

Formic acid
Acetic acid

H +, H +