How many molecules are there in 122 grams of #NO_2#?

1 Answer
Nov 14, 2015

Molecular mass of nitric oxide is #46.1# #g#. So number of molecules #=# #(122*g)/(46.1*g) xx N_A#. #N_A# is Avogadro's number.

Explanation:

Avogadro's number, #N_A# #=# #6.02214# #xx# #10^23#. It is a fact that if I have Avogadro's number of hydrogen atoms (i.e. #""^1H# atoms) I have a #1# #g# mass precisely. So your answer is #(122*g)/(46.1*g) xx N_A# molecules (pretty large but not infinite). If I asked for the number of nitrogen atoms how many would I have? If I asked for the number of oxygen atoms how many would I have? And what if I asked for the total number of atoms?