I had a multiple choice problem on my pop quiz. How many oxygen atoms are there in .00334 grams of CaS04 X 2H2O. The molar mass is 172 g/mol. So .00334/172 = 1.9 x 10-5 moles x 6 since there are 6 oxygen x 6.022 x 1023 = 7.016 x 1019. None of the answer choices had that. Did I do it wrong? I'm gonna talk to my teacher about it tomorrow but its been bothering me lol.