How many moles of iron are in #1.2*10^25# atoms of iron?

1 Answer
Sep 13, 2016

Approx. 20 moles of iron.

Explanation:

There are approx. #6.022xx10^23# iron atoms per mole of ion. This quantity, this number of iron atoms has a mass of #55.85*g#. And of course, when we quote the mass of iron we say #55.85*g*mol^-1#.

So,
#(1.2xx10^25*"atoms of iron")/(6.022xx10^23*"iron atoms per mole")# #~=# #20*"moles"#