Acids
- Acids form a class of chemical substances which contain hydrogen ions in aqueous solution, H+ (aq), as the only positive ion.
- Acids are usually classified into mineral or organic acids.
Mineral Acids
- generally much stronger
- most do not occur naturally
- usually have simpler molecules
Example
- Sulphuric Acid
- Nitric Acid
- Hydrochloric Acid
- Phoshoric Acid
- Carbonic Acid
Organic Acids
- naturally occurring
- found in vegetables, fruit and other foodstuffs
- usually weaker and less corrosive
Example
- Ethanoic Acid
- Citric Acid
- Lactic Acid
- Tartaric Acid
- Acetic Acid
- Acids are substances that form hydrogen ions when dissolved in water.
- A hydrogen ion is actually a proton. Therefore, acids are called the proton donors.
Examples
\[HCl\xrightarrow{{{H_2}O}}{H^ + } + C{l^ – }\]
\[HN{O_3}\xrightarrow{{{H_2}O}}{H^ + } + N{O_3}^ – \]
\[{H_2}S{O_4}\xrightarrow{{{H_2}O}}2{H^ + } + S{O_4}^{2 – }\]
The hydrogen ions produced will combine with the water molecule to form hydroxonium ions (H3O+)
\[{H^ + } + {H_2}O \to {H_3}{O^ + }\]
Therefore the reaction can also be written as
\[HCl + {H_2}O \to {H_3}{O^ + } + C{l^ – }\]
\[HN{O_3} + {H_2}O \to {H_3}{O^ + } + N{O_3}^ – \]
\[{H_2}S{O_4} + 2{H_2}O \to 2{H_3}{O^ + } + S{O_4}^{2 – }\]