number of molecules in 60g of NO2

Question

 I need help on my chemistry homework for college

Answer 1

Look up in your chemistry book the atomic weights of N and O.  Find the molecular weight of NO₂ from

 

W = (N) + 2(O)

 

where (N) is the atomic weight of N and (O) is the atomic weight of O.

 

Divide the mass of 60 g by the molecular weight.  That gives you the number of moles of NO₂.  Multiply the number of moles of NO₂ by Avogadro's number, which is 6.02 x 10²³.  That gives you the number of molecules of NO₂.