As we know that a substance is a composition of different atoms. We have to represent this substance with the help of atomic symbols. The representation of a substance with the help of atomic symbols is known as the chemical formula of that substance. These chemical formulas are divided into two types. The first type of the chemical formula is known as the molecular formula and the second type of the chemical formula is known as the empirical formula. Here, we will explain the difference between the molecular formula and the empirical formula.
What is Molecular Formula?
What is the Empirical Formula?
Difference Between Empirical Formula and Molecular Formula
i. Representation of Atoms
Molecular formulas and empirical formulas show different kinds of representations of atoms. In a molecular formula, we represent the total number of atoms in each compound. On the other hand, with the help of the empirical formula, we represent the simplest whole-number ratio of the atoms in a compound.
The molecular formulas of different compounds are different but the empirical formulas of different compounds can be identical. The molecular formulas of glucose, ribose, and acetic acid are C6H12O6, C5H10O5, and C2H4O2. These examples of molecular formulas show that each compound has a different molecular formula. On the other hand, when we find the simplest whole-number ratios of all the atoms of these compounds, we know that all of these compounds have a similar molecular formula which is CH2O.
With the help of molecular formulas, we can represent the structure of the elements of a compound. On the other hand, with the help of empirical formula, we just express the elements which are forming this compound.
Both molecular and empirical formulas of a compound can be similar. For example, CH2O is the molecular formula of formaldehyde. As we can’t simplify the atoms of this compound, therefore, CH2O is also the empirical formula of formaldehyde.
We don’t use the empirical formula in the chemical reactions but we are using molecular formulas in the chemical reactions. Its reason is that in a chemical reaction, we have to balance atoms on both sides of the reaction. If we are using the empirical formula, it is difficult for us to balance both sides of the equation.
We can derive the empirical formula of a compound by deriving weight percentages of the elements in the compound. On the other hand, we derive the molecular formula of a compound from its empirical formula.
To write the name of a compound, we give preference to the molecular formula over the empirical formula. Its reason is that we can’t represent more than one compound with the help of a molecular formula. On the other hand, an empirical formula can represent more than one compound.
The molecular formula of Hydrogen Peroxide is H2O2. On the other hand, its empirical formula is HO. Its reason is that the simplest whole-number ratio between its atoms 2:2 is 1:1.