Svante August Arrhenius, a Swedish physical chemist and astrophysicist, was the first to discover and describe the phenomenon of the decomposition of acids in 1887. The researcher observed a relationship between the structure of chemical substances and electrical conductivity. The scientist classified bases, salts and acids that undergo the dissociation process, among others, as electrolytes, i.e. electrical conductors. This article will answer the following question: what is the dissociation of acids?
What is the ionic dissociation of acids?
Thanks to the research carried by Svante August Arrhenius and his followers (including: Peter Debye and Erich Hückel), we know today what ionic dissociation is and what happens in its course. It is a process in which the molecules of electrolytic solutions break up into:
- positive ions (hydrogen cations) and
- negative ions (acid radical anions).
Another name of the process is electrolytic dissociation, since the solution obtained after the separation into ions conducts an electric current. Under what conditions does the ionic dissociation of acids occur? Those oxy-acids and hydracids that have ionic (electrovalent) bonds undergo chemical decomposition. The ionic dissociation reaction also occurs in compounds with polar covalent bonds (in such bonds the electrons concentrate around atoms with higher electronegativity).
The process of the ionic dissociation of acids and the conductivity of electrolytes
To describe the dissociation of acids, scientists employ the term of degree of dissociation. This value expresses the ratio of the moles of molecules dissociated to the total number of moles in the solution. What does the degree of dissociation depend on? The following factors determine the degree of dissociation: the type of electrolyte, the solvent used, the density and temperature of the liquid.
Acid solutions undergo decomposition in their own way and are classified as:
- strong electrolytes – those dissociate completely,
- weak electrolytes – those only partially dissociate.
Strong electrolytes include: nitric, hydrochloric, perchloric, sulfuric and hydrobromic acids. In what compounds does the weak dissociation of acids occur? The examples include both organic and inorganic acids such as: carbonic, phosphoric, sulfurous, acetic or formic acids.
Ionic dissociation of acids – examples
How is the electrolytic dissociation of acids performed? To carry out the process, a chemist needs water and an acid. Water (H2O) gradually splits up the structure of acid molecules. Once the dissociation is finished, the aqueous solution of an acid becomes an electrolyte.
What ions do acid solutions separate into? Let us discuss this on selected examples of common electrolytes:
- under the influence of water, sulfuric acid dissociates into hydrogen cations and sulfate anions,
- nitric acid in water breaks into hydrogen cations and nitrate anions,
- water dissolves carbonic acid into hydrogen cations and carbonate anions.
Industry and chemistry – ionic dissociation and its application
Electrolytes that are formed as a result of the dissociation of acids have a number of uses in the chemical, automotive or pharmaceutical industries. They are used, for example, for the production of laboratory reagents, cleaners and detergents, solvents as well as acid or lead accumulators.
Acids in the product range offered by the PCC Group
As already mentioned, acids and electrolytes formed as a result of dissociation have many industrial applications. Thus, the PCC Group’s product range includes a number of acid derivatives. Examples include phosphoric esters (derived from phosphoric acid); those are useful additives added to lubricants and MWF. Our product range includes two product series based on phosphoric esters: CHEMfac and EXOfos. Apart from the above-mentioned chemicals, the PCC Group’s Product Portal also includes a number of other interesting proposals e.g. based on hydrochloric acid. Read more about our full product range!