- Characteristics of ternary compounds
- Bases and acids
- Nomenclature
- Bases
- Oxoacids
- Oxisales
- Training
- Examples
- References
The ternary compounds are those which are composed of three different atoms or ions. They can be very diverse, from acidic or basic substances, to metal alloys, minerals or modern materials. The three atoms can either belong to the same group on the periodic table, or they can come from arbitrary locations.
However, for the ternary compound to be produced there must be a chemical affinity between its atoms. Not all are compatible with each other, and therefore one cannot simply choose at random which three will make up and define the compound or mixture (assuming the lack of covalent bonds).
General and random formula for ternary compounds. Source: Gabriel Bolívar.
For example, three letters are randomly chosen to govern a ternary compound ABC (upper image). The subscripts n, m and p indicate the stoichiometric relationships between the atoms or ions A, B and C. By varying the values of these subscripts, and the identities of the letters, a myriad of ternary compounds are obtained.
However, the formula A n B m C p will only be valid if it complies with electroneutrality; that is, the sum of their charges must be equal to zero. With this in mind, there are physical (and chemical) limitations that dictate whether or not the formation of said ternary compound is possible.
Characteristics of ternary compounds
Its characteristics are not general but vary depending on their chemical nature. For example, oxo acids and bases are ternary compounds, and each one of them shares or does not share a number of representative characteristics.
Now, before a hypothetical compound ABC, this can be ionic, if the electronegativity differences between A, B and C are not great; or covalent, with ABC bonds. The latter are given in infinite examples within organic chemistry, as in the case of alcohols, phenols, ethers, carbohydrates, etc., whose formulas can be described with C n H m O p.
Thus, the characteristics are very varied and vary greatly from one ternary compound to another. The compound C n H m O p is said to be oxygenated; while C n H m N p, on the other hand, is nitrogenous (it is an amine). Other compounds may be sulfurized, phosphorous, fluoridated, or have a marked metallic character.
Bases and acids
Advancing in the field of inorganic chemistry, we have the metallic bases, M n O m H p. Given the simplicity of these compounds, the use of the subscripts n, m and p only hinders the interpretation of the formula.
For example, the base NaOH, considering such subscripts, should be written as Na 1 O 1 H 1 (which would be chaotic). Furthermore, it would be assumed that H is as a H + cation, and not as it actually appears: as part of the OH - anion. Due to the action of OH - on the skin, these bases are soapy and caustic.
Metallic bases are ionic substances, and although they consist of two ions, M n + and OH - (Na + and OH - for NaOH), they are ternary compounds because they have three different atoms.
Acids, on the other hand, are covalent, and their general formula is HAO, where A is usually a non-metallic atom. However, given its ease of ionizing in water, releasing hydrogens, its H + ions corrode and damage the skin.
Nomenclature
Like the characteristics, the nomenclature of ternary compounds is very varied. For that reason, only bases, oxo acids and oxysalts will be considered superficially.
Bases
Metallic bases are mentioned first with the word 'hydroxide' followed by the name of the metal and its valence in Roman numerals in parentheses. Thus, NaOH is sodium hydroxide (I); but since sodium has a single valence of +1, it just stays as sodium hydroxide.
Al (OH) 3, for example, is aluminum (III) hydroxide; and Cu (OH) 2, copper (II) hydroxide. Of course, everything according to the systematic nomenclature.
Oxoacids
Oxoacids have a fairly general formula of the HAO type; but in reality, molecularly they are best described as AOH. The H + is released from the AOH bond.
The traditional nomenclature is as follows: it begins with the word 'acid', followed by the name of the central atom A, preceded or preceded by their respective prefixes (hypo, per) or suffixes (bear, ico) according to whether it works with its lower or higher valences.
For example, the oxo acids of bromine are HBrO, HBrO 2, HBrO 3, and HBrO 4. These are the acids: hypobromous, bromous, bromic and perbromic, respectively. Note that in all of them there are three atoms with different values for their subscripts.
Oxisales
Also called ternary salts, they are the most representative of the ternary compounds. The only difference to mention them is that the suffixes bear and ico, change for ito and ato, respectively. Likewise, H is replaced by a metal cation, the product of acid-base neutralization.
Continuing with bromine, its sodium oxysalts would be: NaBrO, NaBrO 2, NaBrO 3 and NaBrO 4. Their names would be: hypobromite, bromite, bromate and sodium perbromate. Without a doubt, the number of possible oxysalts greatly exceeds that of oxoacids.
Training
Again, each type of ternary compound has its own origin or formation process. However, it is fair to mention that these can only be formed if there is sufficient affinity between the three component atoms. For example, metallic bases exist thanks to electrostatic interactions between cations and OH -.
Something similar happens with acids, which could not be formed if there were no such covalent bond AOH.
In response to the question, how are the main compounds described formed? The direct answer is the following:
- Metal bases are formed when metal oxides dissolve in water, or in an alkaline solution (normally provided by NaOH or ammonia).
- Oxoacids are the product of dissolution of non-metallic oxides in water; among them, CO 2, ClO 2, NO 2, SO 3, P 4 O 10, etc.
- And then, oxysalts arise when oxo acids are alkalized or neutralized with a metal base; from it come the metallic cations that supplant the H +.
Other ternary compounds are formed following a more complicated process, such as with certain alloys or minerals.
Examples
Finally, a series of formulas for different ternary compounds will be displayed as a list:
- Mg (OH) 2
- Cr (OH) 3
- KMnO 4
- Na 3 BO 3
- Cd (OH) 2
- NaNO 3
- FeAsO 4
- BaCr 2 O 7
- H 2 SO 4
- H 2 TeO 4
- HCN
- AgOH
Other less common (and even hypothetical) examples are:
- CoFeCu
- AlGaSn
- UCaPb
- BeMgO 2
The subscripts n, m and p were omitted to avoid complicating the formulas; although in reality, its stoichiometric coefficients (except perhaps for BeMgO 2), can even have decimal values.
References
- Shiver & Atkins. (2008). Inorganic chemistry. (Fourth edition). Mc Graw Hill.
- Whitten, Davis, Peck & Stanley. (2008). Chemistry. (8th ed.). CENGAGE Learning.
- Mrs. Hilfstein. (sf). Ternary Compounds. Recovered from: tenafly.k12.nj.us
- Wikipedia. (2019). Ternary compound. Recovered from: en.wikipedia.org
- Carmen Bello, Arantxa Isasi, Ana Puerto, Germán Tomás and Ruth Vicente. (sf). Ternary compounds. Recovered from: iesdmjac.educa.aragon.es