Acid is a compound which yields hydrogen ion (H+) when dissolved in water.
Acid is sour to the taste and corrosive in nature. The pH value for acids is less than 7.
Generally, all acids readily react with metal to release hydrogen gas. For example, metal zinc reacts with hydrochloric acid to form zinc chloride and hydrogen gas.
Acids react with limestone (CaCO3) to produce carbon dioxide. For example, hydrochloric acid reacts with limestone to produce carbonic acid and calcium chloride.
Acids can be classified into organic and inorganic acids. Acetic acid (CH3COOH) is the best example of an organic acid, and acids produced from minerals are termed as inorganic acids like sulfuric acid (H2SO4), hydrochloric acid (HCl), etc.
Acid converts blue litmus paper to red in color.
Acids have a tendency to corrode metal surfaces quickly.
Phenolphthalein solution is colorless in an acidic solution and turns methyl orange solution to red. Red cabbage juice which is purple in color changes to red in an acidic medium.
Properties of Bases:
Bases are compounds which yield hydroxide ion (OH–) when dissolved in water.
Bases are bitter to taste and corrosive in nature. They feel slippery and soapy.
Bases are the good conductor of electricity and show a pH value of more than 7.
Bases react with oils and grease to form soap molecules.
Bases convert red litmus paper to blue in color.
Bases also have the tendency to corrode metal surfaces.
A reaction between a base and a metal is similar as for acid to form a salt and release hydrogen gas. But this reaction can only occur when a metal is strong enough to displace another metal from its parent constituent.
Phenolphthalein solution turns pink in color in a basic solution. Bases turn methyl orange to yellow. Red cabbage juice which is purple in color changes to yellow in a basic medium.
Properties of salts:
Salts form by the combination of acid and base through neutralization reaction.
The acidic and basic nature of salts depends on the acid and base combined in a neutralization reaction.