Page 1 of 1

### Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 1:40 pm
What's the difference between an empirical and molecular formula and do you have any useful ways to remember the difference?

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 2:18 pm
An empirical formula is the relative number of atoms a molecule has. In other words, it's the proportion of each element in a molecule. For example, glucose's empirical formula would be CH2O because for every carbon atom in a glucose molecule, there are 2 hydrogens and 1 oxygen.

A molecular formula shows the actual number of atoms in a molecule. So, glucose's molecular formula would be C6H12O6. (notice that the molecular formula always retains the same proportion of molecules as the empirical formula!) One way to remember this definition is that the molecular formula shows the contents of the entire molecule.

Also, remember that certain compounds can have the same empirical formula even though their molecular formulas are different.

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 2:29 pm
An empirical formula shows the relevant number of atoms a molecule has *ratio between atoms*, while a molecular formula shows the actual number of atoms *existing atoms*. The molecular formula will always be a multiple of the empirical.

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 3:22 pm
E (empirical) comes before M (molecular) in the alphabet. Empirical formulas are the basis of molecular formulas and come before molecular formulas, just as E comes before M.

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 3:50 pm
Yeah, whats easiest for me to distinguish between the two is to note that the molecular formula is a multiple of its corresponding empirical formula, so the empirical formula basically tells the most simplified version of the ratio of atoms present.

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 4:01 pm
Sometimes I remember them by thinking that an (E)mpirical formula is an (E)asier simplification of the molecular formula’s ratios.

### Re: Difference between empirical and molecular formulas

Posted: Fri Oct 04, 2019 10:07 pm
The empirical formula shows only the ratio/proportions of atoms of the elements present in a molecule. Conversely, the molecular formula shows the exact number of atoms of each element that are present in a molecule. The way that I remember the difference is the when you want to look at a specific molecule, it is unique (only one molecule can have this formula), and thus you want to look for a molecular formula.If I don't remember that strategy, I think that molecular begins with M, as does multiple, and a molecular formula is a multiple of the empirical.