Question

What is meant by strong acids and weak acids? Classify the following into strong acids and weak acids.
\[HCl,C{H_3}COOH,{H_2}S{O_4},HN{O_3},{H_2}C{O_3},{H_2}S{O_3}\]

Answer 1

Hint: Chemical compounds are classified on different bases. One of the classifications is based on the nature of compounds. Based on nature, compounds are classified into acids, bases and neutral compounds. Acids that can dissociate easily give protons, easier is the dissociation, stronger is the acid.

Complete answer:
An acid is a substance that can dissociate easily to give protons \[\left[ {{H^ + }} \right]\]. Stronger is the dissociation of the compound stronger is the acid.
Thus, when an acidic compound dissociates or ionises to form a greater number of hydrogen ions, it can be called a strong acid.
The acidic compound which cannot dissociate easily into hydrogen ions or partially it ionises to give hydrogen ions. Then that acidic compound can be called weak acid.
In the given acids, Hydrochloric acid \[HCl\] is a strong acid, it completely ionises to form a hydrogen ion.
Acetic acid has the molecular formula \[C{H_3}COOH\] and partially ionises to hydrogen ions. Thus, it is a weak acid.
Sulphuric acid has the molecular formula \[{H_2}S{O_4}\] and is a strong acid.
Nitric acid \[\left( {HN{O_3}} \right)\] is a strong acid.
Carbonic acid \[\left( {{H_2}C{O_3}} \right)\] is a weak acid.
Sulphurous acid \[\left( {{H_2}S{O_3}} \right)\] is a weak acid.

Note:
Strong acids will dissociate completely and when the human body gets touched with strong acid it infects the body and the place where there is contact with strong acid gets wounded. Acetic acid with different concentration was of important uses, acetic acid is a weak acid and can be used as vinegar.