The strength of an acid depends on the degree of dissociation of the acid in water to produce hydrogen ions and anions. The pH of an acid solution depends on the concentration of hydrogen ions.
· Strong acid have a higher degree of dissociation.
· A strong acid is an acid which dissociates completely in water to produce a high concentration of hydrogen ions.
· Thus, pH value for strong acid is lower than weak acid.
· Weak acid have a lower degree of dissociation.
· A weak acid is an acid which ionises partially in water to produce a low concentration of hydrogen ions. Only a part of the molecules ionises and the remaining still in covalent molecules.
· Thus, pH value for weak acid is higher than strong acid.
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Examples of strong acid
|HCl||Hydrochloric acid||HNO3||Nitric acid|
|HBr||Hydrobromic acid||H2SO4||Sulfuric acid|
|HI||Hydroiodic acid||HClO4||Perchloric acid|
Examples of weak acid