Nomenclature of Hydrocarbons
Nomenclature means naming, so in this case, nomenclature of hydrocarbons stands for the procedure to name the hydrocarbons, or more importantly organic compounds in general. Before starting with the nomenclature, we should be aware what a hydrocarbon is. A hydrocarbon is an organic compound that is composed of two atoms, those are hydrogen and carbon. You must be thinking why it is important to name the compounds that are only formed by the combination of two atoms, they are just going to be a handful. That is where you are a wrong kid, there are thousands of compounds that can be formed with just the combination of these two atoms and hence it is important for you to learn how to name them.
Need for the nomenclature of Hydrocarbons: since it has been said above that there are thousands of molecules that can be formed along with the combination of just two types of atoms, it became necessary for the researchers to name them because they started to create a lot of confusion among the other molecules. The reason for the confusion is that these molecules can combine in any form they want. Horizontal, parallel, in series or a combination of any of them. Apart from this, the compounds were also started to form isomers which are the mirror images of a certain molecule and hence, For the very same reason, some of the ground rules for the nomenclature were set. They are as follows:
- The fact that anions and cations are the charged particles, that is they have a charge on them be it negative or positive but when a cation and an anion combine together, they might end up making a neutral compound if the magnitude of the charges among them is equal and opposite. The reason this point is on the top of the list is that most of the time, the students are confused as though why is the result of a combination of two charged products resulting into something that is neutral.
- A thing that a name of the compound should indicate is the number of carbon atoms that are present there in the compound. This can be said as the most important factor while naming any organic compound and especially a hydrocarbon.
- The other important thing to mention while naming a hydrocarbon is the other group, more commonly known as the functional group should be highlighted. Hydrogen, on the other hand, is way too common in hydrocarbons that it can be included in the general name itself.
For making it even easier, an organisation named as IUPAC has set down some of the standard rules while naming a hydrocarbon so that when someone else has to read the name of the same compound or after you if someone is interested in continuing that research, there should be no difficulty to that other chemist. In this article, we will be considering only the compounds that have pure carbon and hydrogen atoms attached and have no other functionality group attached to them. For a fun fact, the hydrogen and carbon bond is done over the sp3 orbital and is a sigma hybridised bond. The type of hydrocarbons we aregoing to discuss in this article are alkanes and cycloalkanes.
Alkanes: Since we know that a carbon molecule is able to make three bonds with a hydrogen atom depending on the number of hydrogen atoms attached to it. An alkane is a molecule that does not have any double or triple carbon to hydrogen bond. This simply means that it is having a single bond to each of the hydrogen molecule attached to the individual carbon molecule. To be precise, these are known as unbranched chain molecules. They fall under the group of aliphatic elements which, in short, is everything except the aromatic rings which will be studied further in this article. Some of the characteristics of alkanes are as follows:
- They are usually in the multiples of ch2 that means to every carbon atom, there is one carbon atom attached and two hydrogen atoms. They have a common suffix that goes by “ane” and in the prefix, we put the total number of carbon atoms present in the molecule for eg. if we have on, we call it methane, here metha being the prefix and ane being the suffix that is common for all such kinds of molecules.
- This kind of series, that is the molecules in which one atom is connected after the other and they form a long chain without any connections in the parallel are known to come under the category of homologous.
- The highest ratio of the number of carbon atoms to the number of hydrogen atoms is cNH2N+2 that means for a total of n number of carbon atoms, there can be a maximum of 2 times n plus two atoms of hydrogen at any given time in a molecule. A when such a case is seen, this kind of a molecule is called a saturated hydrocarbon molecule because the total number of bond possibilities with any other atom has been fulfilled and hence it is called as saturated.
Please also note that sometimes the halogen atoms can be added to them like fluorine or chlorine and so on, the atoms that are close to the noble gases in the periodic table. When such a substitute is added to them, they can be easily named by adding the half of the name of the substituent atom in the front like if bromine is added, bromo is added in the name of the compound.
Cycloalkanes: this is the term given to the carbon chains which form a circle so that the stability of the atoms could be increased in a natural way. Some of the points that are needed to be kept in mind while naming a cycloalkane as follows:
- Nothing strange has to be done while naming such compounds, the only cyclo has to be added in the front of the hydrocarbon.
- The general formula for such a compound will be cNh2n that means for every single carbon atom, two hydrogen atoms are permitted at the maximum. However, it is not necessary that the atoms have to be twice the number of carbons. They can be less too, in that case, the carbon will form double or triple bonds with the hydrogen atoms.
We hope that with the help of this basic article, you will be able to name some of the very common organic compounds that come under the category of hydrocarbons, be it alkanes or cycloalkanes.
