Everything in this universe is made up of atoms and molecules. Even our own body itself is made up of collective atoms. Chemical compounds play a major role in differentiating one substance from another.
Depending upon the properties of a substance like specific weight and volume, they will vary from each other. When it comes to naming chemical compounds, we have to follow certain standard rules. Here is a detailed explanation of chemical compounds, the chemical formula of compounds, and more!
What is a chemical compound?
A chemical compound is a mixture of more than two atoms or molecules forming an element. One can break these compounds into simpler substances by performing suitable chemical processes.
Chemical compounds examples
- Sodium chloride
- Nitrogen gas
- Water
Types of compounds
There are two types of compounds based on the properties of the substance.
- Ionic compound
- Covalent compound
Ionic Compound
Ionic compounds are charged particles formed when electrons are transferred between atoms of different elements. The ions that make up an ionic compound are a cation and an anion, where cation is a positive ion, whereas anion is a negative ion.
For example, In sodium chloride Na+ is cation and Cl- is an anion (Cl-). In magnesium hydroxide, Mg2+ is a cation and OH- is an anion.
Rules for writing Chemical Formula of Ionic Compounds
The following are a set of procedures for writing the chemical formula of Ionic Compounds
- The cation should be written first, followed by the monatomic or polyatomic anion.
- The subscripts in the formula must be balanced and should produce an electrically neutral formula unit. (Where the total amount of positive charge must be equal to the total amount of negative charge.)
- The subscripts should be the smallest set of possible whole numbers.
- If there is only one polyatomic ion in the formula, parentheses should not be placed around it. For Example, NaNO3, not Na(NO3).
- If there is more than one polyatomic ion in the formula, the ion should be placed inside the parentheses, and the subscript should be placed after the parentheses. For Example, Ca(OH)2, Ba3(PO4)2, etc.
Covalent Compound
A covalent or a molecular compound is a combination of two non-metals that are connected through a covalent chemical bond. The elements form a compound by sharing electrons, which results in an electrically neutral molecule. In covalent bonds, two elements can combine in several different ways to form completely different compounds (which cannot be done in ionic compounds).
For example, carbon shares electrons with one oxygen to form CO (carbon monoxide), or with two oxygens to form CO2 (carbon dioxide).
For this reason, the specification of a number of elements within the compound is necessary.
Rules for writing Chemical Formula of Covalent Compounds
The following are a set of procedures for writing the chemical formula of Covalent Compounds
- The more electropositive element should be placed first (the one further to the left on the periodic table), followed by the more electronegative element (the one further to the right on the periodic table).
- If the compound consists of oxygen and a halogen, the halogen should be placed first.
- If both elements of the compound are in the same group, the one with the higher period number should be placed first.
- The first element in the chemical formula of compounds should have the neutral element name, and the second one should be named by replacing the end of the neutral element name with -ide.
- A prefix should be used before each element name to indicate the number of atoms in the compound.
For example:
1 | mono- |
2 | di- |
3 | tri- |
4 | tetra- |
5 | penta- |
6 | hexa- |
7 | hepta- |
8 | octa- |
9 | nona- |
10 | deca- |
- If there is only one first element in the formula, the mono- prefix can be dropped or removed.
The following are some of the covalent chemical compounds examples
SO2 | Sulphur dioxide |
SO3 | Sulphur trioxide |
N2O | Dinitrogen monoxide |
NO | Nitrogen monoxide |
NO2 | Nitrogen dioxide |
N2O4 | Dinitrogen tetroxide |
N2O5 | Dinitrogen pentoxide |
Conclusion
Chemical compounds play an important role in differentiating one substance from another. Each chemical compound varies based on properties like specific weight and volume. The ionic compounds are a combination of cations and anions, where cations (the positively charged) are named first followed by the anions (the negatively charged). Whereas in the covalent compounds, the two nonmetals combine in several different ways to form several different chemical compounds. The more electropositive elements are placed first followed by the more electronegative elements specifying the number of atoms in it. Therefore naming the chemical compounds plays a major role in the field of chemistry.