How to Calculate Oxidation Number

Oxidation numbers and their identification is an important concept in chemistry. 

During an electrochemical reaction, the atoms either lose or gain electrons depending on whatever helps in defining the oxidation state of the compound. 

The oxidation number calculator helps in calculating the oxidation number of an element in a compound and is crucial for the systematic nomenclature of chemical compounds. 

An oxidation number is a number assigned to each of the atoms in a substance and loosely refers to the electrons shuffling from one atom to another in a reaction. The oxidation number rules help in calculating the oxidation number of an atom. 

The oxidation number chart and the rules for calculation will be discussed in detail in the following sections of the article.  

Oxidation Number Chart and Assigning the Oxidation Number 

The oxidation number chart helps in determining how the oxidation number is assigned to each of the groups in the periodic table. The oxidation number of the elements for the groups differ depending on their location in the periodic table.

• The oxidation number chart indicates that the oxidation number of the element is either negative or positive. 
• The metals have a positive oxidation number whereas the non-metals have either a negative or positive oxidation number. 
• In the case of the s-block in the oxidation number chart, the alkali metals show a +1 oxidation state, whereas the alkali earth metals show an oxidation state of +2. Examples of alkali metals include lithium, sodium, rubidium, potassium, etc. Examples of the alkali earth metals include magnesium, calcium, barium, beryllium etc. 
• In the p-block, the group 3 elements include boron, indium, gallium, aluminium, and thallium. They have an oxidation number of +3. 
• Generally, from group IA to IV A group in the oxidation number chart, the common oxidation number of an element is equal to the group number. For example, the oxidation number of the IV A group element is +4. 
• However, for groups V A to VIII-A, common oxidation is presented with the help of the formulae (group number – 8). Hence, for group VIIA, the oxidation number is -1
• Depending on the compound and the bonding of the atom or element in a compound, the oxidation number varies. 

Use of the Oxidation Number Calculator 

Each of the elements in a compound has a certain oxidation number. The sum of all the oxidation numbers of the atom in a compound is always zero. It is a type of chemical calculator used for finding the oxidation number of all elements in a compound. The oxidation number calculator helps calculate the oxidation number of elements faster and gives results in just a few seconds.

It is easy to use the oxidation number calculator. 

• Write the chemical formulae of the compound and make sure all the letters or numbers are used precisely.
• Always ensure to write the correct number of atoms for each element in the compound. Make sure to mention the exact number of atoms for correct calculation. It is recommended to use an equation balancer.
• Do not use unnecessary brackets or parentheses when writing the chemical formula.
• Once the formulae for the compound are double-checked for accuracy, click on the calculate button to display the results.

The calculator and its design are based on the Lewis diagram which helps with the calculation of the oxidation number of an element. The calculator shows how the atoms and their valence electrons interact with each other.

Oxidation Number Rules

The calculation of the oxidation number is done by applying several oxidation number rules. It is important to understand the rules to calculate the oxidation number. Here are the crucial rules to follow:

• The sum of the oxidation number for all the atoms in an element in its free or uncombined state is zero. 
• One of the most important conventions in writing formulae is that the cation is written first, followed by anion. 
• The oxidation number of an atom in its elementary form is always zero. 
• The oxidation number for monoatomic ions is equal to the charge of the ion. 
• The oxidation number of alkali metals within a molecule or compound is +1. The oxidation number of alkaline earth metals is +2. 
• In most of the molecules, the oxidation number of oxygen is -2. However, there are two exceptions to which different rules apply: 

1. In the case of peroxides, the oxygen atom has an oxidation number of -1.
2. For superoxide, the oxygen atom has an oxidation number of -(1/2).
3. In ozonides, the oxidation number of each oxygen atom is -(1/3). 

• The oxidation number of H in any compound is always +1 except for metal hydrides. For example, in the case of NaH, the oxidation number of H is -1.
• In the case of an ionic compound, the sum of the oxidation state of all atoms is equal to the total charge of the compound.
• The maximum oxidation number of any element is equal to its group number, but not in the case of oxygen and fluorine.

Conclusion 

The oxidation number rules help in the calculation of the oxidation number of the elements present in a compound. The use of a calculator for calculating the oxidation number is a fast, accurate, and efficient way to calculate the oxidation number. In the oxidation number chart, depending on its position in the periodic chart, the oxidation state varies. The calculation of the oxidation number in the calculator requires accurate input of the compound ensuring several atoms are correctly used.