Chemical Equations-Balancing of a Chemical Equation

A chemical equation is made up of the chemical formulae of the reactants reflecting on the left side and the products reflecting on the right side. An arrow symbol “→” , commonly read  as ‘yields’, separates the reactants from the products. A “+” sign separates the chemical formulas of each particular substance from those of others.

Chemical Equation

A chemical equation is a representational description of a chemical reaction wherein the reactants and products are expressed by chemical equations.

2H2 + O2 → 2H2O is an example of a chemical equation that explains the interaction between hydrogen and oxygen to form water.

The reactant side of the chemical equation is to the left of the arrow sign, while the product side is to the right side of the arrow symbol.

Coefficient of Stoichiometry

The total number of molecules of a chemical reactive species which engages in a chemical reaction is represented by a stoichiometric coefficient. It gives a proportion of the responding species to the reaction products.

Let’s take an example: In the chemical reaction described by the balanced chemical equation CH4 + 2O2 → CO2 + 2H2O, the stoichiometric coefficient of O2 and H2O is 2 and the stoichiometric coefficient of CH4 and CO2 is 1.

In a balanced chemical equation, the overall number of atoms of an element contained in a species is directly proportional to the product of the stoichiometric coefficient and the amount of atoms of an element in one molecule of a species.

The total number of oxygen atoms in the reactive species ‘‘2O2‘‘, for example, is 4.

Stoichiometric coefficients are assigned in a way that matches the overall number of atoms of each element on the reactant and product ends when trying to balance chemical equations.

Algebraic Method of Balancing a Chemical Equation

This approach of balancing chemical equations entails introducing algebraic variables to each species in the imbalanced chemical equation as stoichiometric coefficients.

• Step 1: The chemical formulae of the products and reactants must be written down to obtain the imbalanced chemical equation.

The unbalanced chemical equation for example is considered as  C6H12O6 + O2 → CO2 + H2O

• Step 2: In the imbalanced chemical equation, algebraic variables as stoichiometric coefficients are assigned to each species.

In line with our above example, with algebraic variables assigned to each species, the equation is represented as a C6H12O6 + bO2 → cCO2 + dH2O

• Step 3: The equations for every element are put together to form a set of equations.

6a = c (is considered for carbon); 6a = d (is considered for hydrogen); 6a + 2b = 2c + d (is considered for oxygen)

• Step 4: The smallest value of every variable is found. These values can then be replaced in the chemical equation which was generated in step 2.

Hence,  aC6H12O6 + bO2 → cCO2 + dH2O becomes a balanced chemical equation as C6H12O6 + 6O2 → 6CO2 + 6H2O

The Traditional Method of Balancing a Chemical Equation:

The very first step in balancing chemical equations is to get the imbalanced equation in its completeness.

• Step 1: Determine the unbalanced equation using the chemical formulae of the reactants and products.

The unbalanced chemical equation for example is considered as  C3H8 + O2 → CO2 + H2O

• Step 2: Compare the total amount of atoms of each element on the reactant and product sides.

In line with our above example, with algebraic variables assigned to each species, the equation is represented as C3H8 + O2 → CO2 + H2O

• Step 3: Stoichiometric coefficients are now applied to compounds that contain an element with a varying atomic mass on the reactant and product sides.
• Step 4: Step 3 is continued until the total atoms of each element of the interacting elements on the reactant and product sides is equal.
• Step 5: After all the individual components have been balanced, the total number of atoms of the elements on the reactant side and product sides is evaluated again. The chemical equation is said to be balanced if there are no imbalances.

Hence the balanced chemical equation is C3H8 + 5O2 → 3CO2 + 4H2O

Conclusion

A chemical equation is made up of the chemical formulae of the reactants reflecting on the left side and the products reflecting on the right side. An arrow symbol “→” , commonly read  as ‘yields’, separates the reactants from the products. A “+” sign separates the chemical formulas of each particular substance from those of others. Each compound’s or molecule’s state of matter is given in subscript next to the compound by an abbreviation in parenthesis. To satisfy the law of conservation of matter, which confirms that matter is in no way lost or newly created in a closed system, chemical equations must be balanced.