posted by megan .
would the ratio of moles of Cu:moles of CuCl2 differ from atoms of Cu:formula units of CuCl2? Why or Why not?
No they would not. Both of the formulas have the same ratio of Cu to Cl2 in moles and in atoms. 1 mole will always equal 6.02x10^23 atoms per mole, and two moles will always equal twice as many atoms as their are in 1 mole; this will always be a constant.