Difference Between Acid and Base

Acids may be defined as the compounds that donate an ion of hydrogen (H+) to another compound (usually called a base). Conventionally, an acid used to be known as the chemical compound that once dissolved in water, produces a solution that has a low activity of hydrogen ion than water in its purest form.

A base on the other hand which is soluble in nature is termed as an alkali. Liquids that are volatile (acids) once mixed with certain substances would produce salts. The produced salts would form a base that are concrete and thus they were termed as bases. Acids usually are H+ donors while Bases are H+ acceptors.





An acid is any chemical compound once dissolved in water produces a solution with hydrogen ion activity more than purified water

A base is an aqueous substance that could absorb hydrogen ions.


Relies on the concentration of the hydronium ions

Relies on the concentration of the hydroxide ions


Acetic acid CH3COOH and sulphuric acid

Sodium Hydroxide (NaOH) and Ammonia

Characteristics (Physical)

Would depend upon the temperature acids would look solid, liquid or in the form of gas. It would also have a sour taste.

Bases would feel slippery and solid in nature except ammonia which is gaseous. It would have a bitter taste.


Acids would release hydrogen ions (H+) when mixed with water

Bases would release hydroxide ions (OH-) when mixed with water

Test with Litmus

Would turn litmus paper red

Would turn litmus paper blue