What Does the Dots and Numbers Mean in this Chemical Formula?

[Nim]

I don't get this:

"Its empirical formula is
C 10 H 17 N 3 S • 2 HCl • H 2 O"

What is with those dots? And the middle part has a number before a letter...

 

[Monique]

Well, it means you have got a mixture of molecules.

$C_{10}H_{17}N_3S$ with two molecules of $HCl$ and a single molecule of $H_2O$

 

[ravenprp]

The dots in the chemical formula indicate that there are multiple components present in the compound. In this case, there are three components: C10H17N3S, 2HCl, and H2O. The numbers before the letters indicate the number of atoms of each element present in the compound. For example, there are 10 carbon atoms, 17 hydrogen atoms, 3 nitrogen atoms, and 1 sulfur atom in the first component (C10H17N3S). The "2" before HCl indicates that there are two molecules of hydrochloric acid present, and the "1" before H2O indicates that there is one molecule of water present. This strange chemical formula is just a way to represent the different components and their ratios in the compound.