Chemical formulas provide a lot of information about chemical substances, such as how many and what atoms they are made of, as well as the way the atoms are arranged. In this lesson, we'll discuss the different types of chemical formulas.
What is a Chemical Formula?
We encounter chemical substances and compounds everyday. The substances under the kitchen sink that we use to clean our houses as well as those that are staples in our medicine cabinet are made up of chemical substances. These chemicals are made up of a fixed proportion of atoms, and these atoms are arranged in a certain way. In order to figure out what these proportions are and how they are arranged for any given substance, we need to know the chemical formula of the substance or compound.
Chemical Substances in Our Medicine Cabinet
A compound is a substance made up of a definite proportion of two or more elements. A chemical formula tells us the number of atoms of each element in a compound. It contains the symbols of the atoms of the elements present in the compound as well as how many there are for each element in the form of subscripts.
Compounds and Chemical Formulas
Each chemical substance has a specific chemical composition, so these chemical substances have their own chemical formula. Let's take a look at the chemical formula of glucose: there are 12 carbon (C) atoms, 22 hydrogen (H) atoms and 11 oxygen (O) atoms.
There are different types of chemical formulas and each type gives us different information about a chemical substance. The different types of chemical formulas include: molecular, empirical, structural and condensed structural formulas. We'll discuss each of these different types as well as go over a few examples.
Molecular Formula
The molecular formula, sometimes known as the true formula, tells us the actual number of the different elements in one molecule of a compound. In a molecular formula, each element is written as their symbols in the periodic table, and the number of atoms for each element is shown by the subscript (the small number to the lower right of the element). Here are some examples of molecular formulas:
Molecular Formula
If we look at butane, we see it has 4 carbon (C) atoms and 10 hydrogen (H) atoms.
Empirical Formula
The word empirical is defined as something that is verified by observation. In chemistry, we verify facts by performing experiments. So, the empirical formula is defined as the simplest ratio of whole numbers of elements that make up a compound, and this type of formula is derived from experimental data.
Just like how we simplify fractions in math class, in chemistry we can simplify formulas as well. In this case, let's look at the molecular formula of glucose: