Question

How many oxygen atoms are present in 0.5 mole of pentahydrated copper(ii) sulfate, cuso4.5h2o?

Answer 1

pentahydrated copper(ii) sulfate, CuSO4.5H2O

1 mole of pentahydrated copper(ii) sulfate contains 9 mole O  

Thus 0.5 mole pentahydrated copper(ii) sulfate *9 mole O/1 Mole pentahydrated copper(ii) sulfate

= 4.5 mole O  

1 mole = 6.022*910^23 atoms

Therefore  

4.5 mole O  * 6.022*910^23 atoms/ 1 mole

= 2.71*10^24 atoms O