Differences Between a Molecular and Structural Formula

 Molecular vs Structural Formula

Perhaps during your chemistry class you had a headache with molecular and structural formulas. Even I had encountered the same problem. For starters, molecular and structural formulas are somewhat hard to understand, especially if you are not quite interested in them. In this article, let us have a quick refresher. Read on to find out what are molecular and structural formulas are and their differences between one another.

Molecular and structural formulas deal with atoms and molecules. We all know that molecules are formed when atoms are combined altogether. Atoms combine through ionic or covalent bonds. Though atoms combine, it does not mean that molecules are made up of the same kind of atoms. To express what a particular molecule consists of, we use the molecular formulas and the structural formulas.

A molecular formula is one of the simplest ways to express the writing of complex molecules. With a molecular formula, it can specify the actual number of atoms of each element in a molecule. In a particular element, it contains one or more letter symbols which are very useful in determining that particular element. When writing the molecular formula, you have to write the symbols for all the elements that are contained within a molecule. And to the right of each element, you will indicate how many atoms of each element are present.

For example, we have a glucose molecule. Its molecular formula is C6H12O6. This molecular formula means that glucose has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms. “C” is the symbol for “carbon.” “H” is the symbol for “hydrogen.” “O” is the symbol for “oxygen.” What then is the molecular formula for the water molecule? A water molecule has 2 hydrogen atoms and it has 1 oxygen atom. That would be H2O. When there is only one atom of a particular element, the number “1” does not need to be written in the molecular formula.

Constructing the molecular formula seems pretty easy. As long as you know the symbol for each element and how many atoms there are in a particular molecule, you’ll never go wrong. Though we already know the number of atoms of each element in a particular molecule, the molecular formula is not enough to define how the atoms are arranged in a molecule. We don’t know whether the atoms are bonded to one other. With that, structural formulas help us.

As its name implies, a structural formula shows the structure of how atoms and molecules are built. It is like a simple sketch to visualize the image of a molecule. A structural formula also indicates where and how each atom is placed. To create the structural formula, you also need to know the symbol for each element. The atoms in each element are represented by their symbols. The symbols are then connected by lines. These lines are the bonds of each atom. Sometimes there are molecules with the same number of atoms in each element. To tell them apart, the structural formula is the best way to determine it.

Summary:

  1. Molecular and structural formulas deal with atoms and molecules.

  2. To express what a particular molecule consists of, we use the molecular formulas and the structural formulas.

  3. With a molecular formula, it can specify the actual number of atoms of each element in a molecule.

  4. When writing the molecular formula, you have to write the symbols for all the elements that are contained within a molecule.

  5. A structural formula shows the structure of how atoms and molecules are built. It is like a simple sketch to visualize the image of a molecule.