And last, I'll look at my oxygen,

17 divided by 16, and I get 1.06 moles of oxygen.

So now, I've assumed my 100 gram sample and converted to mass.

I've converted from mass to moles.

Now I need to divide, and I'm going to divide by the least number of moles.

So I'm going to divide each of these numbers by

1.06 because that's the smallest value.

Remember I'm just trying to find the smallest whole number ratio between

the elements in the compound.

So I have 6.38 divided by 1.06, and I end up with carbon 6,

hydrogen 6, oxygen 1.

Now we already have our subscripts for

that empirical formula because what we ended up with were nice whole numbers.

If we don't, then we have to look at multiplying throughout by

some value in order to get whole number subscripts.

For example, if we had C2H4.5, we

would need to actually multiply through by 2 so that

I can get rid of this fraction because we can't have a decimal in our subscript.

So if I multiply through by 2, I end up with C4H9.

Now I have my smallest, whole number ratio between the elements in the compound.

Generally, you will only multiply by a number such as 2, 3, or 4.

If you find yourself continuing to multiply to get to the smallest whole

number ratio, check your math and make sure you have the correct number of moles.