Acids, Bases and Salts - Key Concepts

Vocabulary flashcards covering the definitions, types, properties, and indicators of acids and bases.

Acids

Substances that donate $H^+$ ions during a chemical reaction, taste sour, are corrosive in nature, have a pH less than $7$, and turn blue litmus red.

Bases

Substances that receive $H^+$ ions or donate $OH^-$ ions during a chemical reaction, taste bitter, feel soapy to the touch, and turn red litmus blue.

Organic Acids

Natural acids, examples of which include oxalic acid, tartaric acid, citric acid, and acetic acid.

Mineral Acids

Artificial acids, such as hydrochloric acid ($HCl$), sulphuric acid ($H_2SO_4$), nitric acid ($HNO_3$), and phosphoric acid ($H_3PO_4$).

Litmus Solution

A purple dye extracted from lichen, a plant belonging to the division Thallophyta, that is commonly used as an indicator and remains purple when neutral.

Acid-Base Indicators

Substances (including natural materials and synthetic dyes) that change colour to indicate the presence of an acid or a base in a solution.

Turmeric

A natural indicator that turns reddish-brown when in contact with a base (such as soap) and turns yellow again when washed with plenty of water.

Phenolphthalein

A synthetic indicator that is colourless in nature, remains colourless in acids, and turns pink in bases.

Methyl Orange

A synthetic indicator that is orange in nature and is used to test for the presence of acids and bases.

Neutralisation Reaction

A process in which acids and bases nullify each other's effects, such as when baking soda solution is used as a remedy for acidity caused by overeating.