[fifa2005xbox]

Question: Find the total number of atoms in a sample of cocaine hydrochloride, C17H22ClNO4, of mass 23.0 mg.

This is what I did:
-I found the total number of grams in the sample which was 339.8. I converted this to mg and and got 339,800 mg in a mole.

I divided 23 mg sample / 339,800 = 6.768 x 10^-5 mole. This is my sample so I then multiplied this by 6.022x10^23 atoms and got 4.08 x 10^19. This was a wrong answer.

Where am I going wrong? I am very frustrated and have spent over four hours doing this question. It is due today:(

[Borek]

I found the total number of grams in the sample which was 339.8.

No, you have found molar mass of the substance. Mass of the sample was given.

I converted this to mg and and got 339,800 mg in a mole.

OK

I divided 23 mg sample / 339,800 = 6.768 x 10^-5 mole.

Correct.

This is my sample so I then multiplied this by 6.022x10^23 atoms and got 4.08 x 10^19. This was a wrong answer.

You are close, just reread the question. What you have calculated is a number of cocaine hydrochloride molecules. How many atoms (of all kinds) in one cocaine hydrochloride molecule?