Question

Guys. I have another chemistry question that I am unsure with. I would appreciate it if you could help me with working out. Thanks.

A sample of ethane, C2H6, contains 9.6 * 10 ^ 22 atoms. How many mole of ethane is present in the sample?

Why do I need to divide (9.6*10^22) by 8 before I plug it into this equation: n = N/N(A)?

Answer 1

because each molecule contains 8 atoms. When figuring the mol wt, you need to use the number of molecules, not atoms.