[BodegaMSU]

I need to understand how do do the following.  Describe the # of atoms in the makeup of a specific compound.  I need to do it for lead acetate.  I do not just want an answer, I would please appreciate an explanation of how to di it.  Thank you very much.

Michael Draggich
draggich@msu.edu

[jdurg]

Okay.  What is a chemical formula?  When you write out NaCl, what are you writing out?  

What you're writing out is what atoms make up one unti of sodium chloride.  For NaCl, the total number of atoms is two; one sodium atom (Na) and one chlorine atom (Cl).  What about something like water?  Well, water would be H2O.  You have one oxygen atom, and two hydrogen atoms.  

Now let's look at something a bit more complex like Aluminum Sulphate.  Aluminum is just a single atom making up an ion with a charge of +3.  Sulphate is a polyatomic ion with a charge of -2, so it's an ion made of many different atoms.  If we write the chemical formula for aluminum sulphate, we'll get Al2(SO4)3.  We need three sulphate ions for every two aluminum ions.  So what is the atom composition?

Al=2
S=3
O=12
Total atoms = 17.

So if you can figure out the formula for lead acetate, it should be pretty easy.