Empirical Molecular Formula
The empirical molecular formula tells the ratio of the elements present in the compound. Empirical formulas are obtained from the analysis of experimental data.
What Is Empirical Molecular Formula?
The empirical molecular formula can be defined as the ratio of the atoms of elements present in the compound. Empirical Formula can be derived from the molecular formula. Empirical Formula is a type of chemical formula. The chemical formula represents the chemical composition of the compound. It tells about the elements that constitute the compound while the empirical molecular formula is the ratio of the atoms of the elements that combine to form compounds. The empirical formula is the simplest formula. It is the ratio of the number of atoms present in the molecule in the smallest possible whole number.
Deriving Empirical Molecular Formula
To determine the empirical molecular formula, first, we have to know the chemical symbol of the element that is present in the compound
Then we should the molecular formula of the compound
Then converting the ratio of atoms into the simplest number will lead to its empirical Formula
Solved Examples
1. The empirical molecular formula for Glucose
It is composed of six carbon atoms, twelve hydrogen atoms, and six oxygen atoms. The chemical symbol of the carbon is C, Hydrogen is H, and Oxygen is O. Thus, the molecular formula of glucose is C6H12O6. The ratio of all the elements present in this compound is C: H: O —> 6: 12: 6. On converting the actual ratio into the simplest possible number, the ratio of the element comes out to be C: H: O —> 1: 2: 1. Therefore, the empirical formula of glucose is CH2O.
2. The empirical molecular formula for acetylene
Acetylene is composed of two carbon atoms and two hydrogen atoms. The chemical symbol of carbon is represented by C and hydrogen by H. Hence, the molecular formula of acetylene is C2H2. The ratio of all the elements present in this compound is C: H —> 2: 2. Converting the actual ratio of the atoms involved in the molecule into the simplest whole number (i.e., C: H —> 1: 1) will lead to its empirical formula. Therefore, the empirical formula of acetylene is CH.