SS 1 Chemistry

Chemistry : SS 1

Topic:  ACIDS

An  acid can be defined as a substance which produces hydrogen ion when dissolved in water.

Arrhenius Concept of An Acid

An acid is a substance that dissociates in water to form hydrogen ions or protons e.g  H2O +HCl – H3O+  + Cl

Bronsted Lowry Concept of An Acid

An acid is a proton donor.

Lewis Concept of acid

An acid is an electron pair acceptor, Lewis acid are molecule that do not contain protons but have empty orbital on the central atom as BF3, AlCl3 and FeCl3

Strength of Acid

1.Strong acid: Acid that completely ionized or disassociated in water under any condition e.g H2SO4, HCl and HNO3. They are strong electrolytes

  1. Weak acid: They are slightly ionized in water e.g CH3COOH. They are weak electrolytes.

Classes of Acid

We have organic and inorganic acid

1.Organic acid: occur naturally in plants and animals. Infact , most of the fruits we eat contains acid. Examples

Organic acid                                             Sources

Ethanoic acid                                            Vinegar

Lactic   acid                                               Sour Milk

Citric acid                                                  Lemon, orange (Unripe)

Amino acid                                               Protein


2  Inorganic acid :Which are also known as mineral acids. These are acid that are derived from one or more inorganic compounds All inorganic acids when dissolved in water produce hydrogen ion(H+) and the conjugate base ions. They are corrosive and highly soluble in water. Examples

  1. Hydrochloric acid.
  2. Nitric acid
  3. Boric acid