A sample of ethane, C2H6, contains a total of 16N atoms, where N = 6.02 × 1023. How much C2H6 is in the
sample?
a. 2.0 g
d. 16 mol
b. 30 g
e. 4 mol
c. 60 g

now this time I did not know how to solve this !

How many atoms are in one ethane molecule? How many would be in one mole of ethane molecules? Which of the possible answers give that number? Give it a try and we will give more help if you need it.

I have the same problem and I did EXACTLY what you said, but I still don't come up with the key answer of 60 grams??

actually I think I just figured it out: there are 8 atoms in one molecule of ethane not 6.022 x 10^23 atoms in one ethane molecule. I think that's where I went wrong, right?

Absolutely correct. Well done!

Thanks! :D