How is the molecular formula different from the structural formula?

The molecular formula shows the number and type of atoms in a molecule, while the structural formula shows their arrangement.

The molecular formula of a compound provides information about the types of atoms present in the molecule and the number of each type of atom. For example, the molecular formula of water is H2O, which tells us that a water molecule contains two hydrogen atoms and one oxygen atom. However, it does not provide any information about how these atoms are arranged or bonded together.

On the other hand, the structural formula provides a visual representation of the molecule's structure, showing how the atoms are arranged and connected. It depicts the bonds between the atoms and can also show the shape of the molecule. For instance, the structural formula of water shows that the two hydrogen atoms are bonded to the oxygen atom, forming a bent shape.

Understanding both the molecular and structural formulas is crucial in chemistry. The molecular formula helps in identifying the compound and its composition, while the structural formula provides insights into the compound's properties and behaviour. For example, the structural formula can help predict how a molecule will interact with other molecules, its polarity, and its reactivity.

In summary, while the molecular formula gives a simple count of the different types of atoms in a molecule, the structural formula provides a more detailed picture of the molecule's structure and the bonds between the atoms. Both are essential tools in the study of chemistry, each providing different, yet complementary, information about a compound.