Strong Acids
Definition
The term strength refers to the extent of ionization of an acid molecule to produce hydrogen ions in aqueous solutions. #ChemistryDefinitions
Definition
Substance which ionizes completely to produce a high concentration of hydrogen ions in aqueous solution. #ChemistryDefinitions
Strong acids:
- Hydrochloric acid
- Nitric acid
- Sulfuric acid
HCl(aq) → H+(aq) + Cl-(aq)
Weak Acids
Definition
Substance which ionizes partially to produce a low concentration of hydrogen ions in aqueous solution. #ChemistryDefinitions
Citric acid - found in citrus fruits - weak acid.
vinegar(ethanoic acid) → weak acid.
Only some CH3COOH molecules will ionize in an aqueous solution.
CH3COOH CH3COO-(aq) + H+(aq)
Weak acids:
- Ethanoic acid
- Carbonic acid
- Phosphoric acid
Note: ” → sign indicates that it is a strong acid, as there is complete ionization in water. ‘⇌’ → indicates it is a weak acid, as there is partial ionization in water.
Strength of acids and concentration of acids
Strength of acid - depends on its degree of ionization
Concentration - related to the number of acid molecules present in a given volume of water.
Strong acid → can be concentrated (large number of acid molecules in given volume) or dilute (small number of acid molecules in a given volume)
Weak acid can also be concentrated or dilute