Page 19 - Curriculum Visions Dynamic Book

Strong and weak acids
Some acids dissociate almost completely when they dissolve in water. These are called strong acids, because the solution will contain a large number of hydrogen ions. Sulphuric acid is an example of a strong acid.
Other acids do not dissociate in water readily, resulting in few hydrogen ions in the solution. These are called weak acids, for example, carbonic acid.
 Strong acids dissociate in water, making a good electrolyte. This
is sulphuric acid being used
as an electrolyte in a battery.
The instrument is a hydrometer, a tube with a bulb on the end. The tube contains a small float which
is designed so that, when acid is drawn into the tube using the bulb, it will register the changes in density of the battery acid. The changes correspond to the state of charge of the battery. Thus, for example, a fully discharged battery will have a low density, whereas a fully charged battery will have a higher density. The hydrometer is colour coded to make it easy for users to see the state of charge of their battery.
Hydrometer
Organic acids
All organic acids contain carbon atoms as
part of their structure, and most are weak acids. When they are put in water only a small proportion of the acid molecules dissociate
at any one time. It is not possible to get a concentrated solution of ions from a weak acid.
 Organic acids are weak acids and therefore do not make good electrolytes. This is why the traditional experiment of making a natural battery by putting two electrodes in a lemon (containing citric acid) is quite safe. Very little current will flow.
corrosive: a substance, either an acid or an alkali, that rapidly attacks a wide range of other substances.
dissociate: to break apart. In the case of acids it means to break up forming hydrogen ions. This is an example of ionisation. Strong acids dissociate completely.
Weak acids are not completely ionised
and a solution of a weak acid has a relatively low concentration of hydrogen ions.
mineral acid: an acid that does not contain carbon and that attacks minerals. Hydrochloric, sulphuric and nitric acids are the main mineral acids.
organic acid: an acid containing carbon and hydrogen.
Also...
Do not confuse strong and weak with concentrated and dilute. Strong refers to an acid that will dissociate well in water. Thus both concentrated nitric acid and dilute nitric acid are strong acids.
Dilute and concentrated refer to the proportion of the acid and the solvent. Dilute hydrochloric acid contains
far more water than concentrated hydrochloric acid.
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