If you have a mole each of #"copper(II) chloride"# and #"copper(II) chloride dihydrate"#, then, CLEARLY, you have the same quantities, the same numbers, of copper and chlorine atoms. If you don't appreciate this, tell us, and someone here will help you.
One mole of #"copper(II) chloride"# differs from one mole of #"copper(II) chloride dihydrate"# in that the latter has 2 moles of water tacked on. The dihydrate is a pale, sky blue solid; the anhydrous form is a beige solid.
The mass of one mole of #"copper(II) chloride"# is #134.45*g#, and that of #"copper(II) chloride dihydrate"#, #170.45*g#.
