Question

One mole of copper(II) Nitrate, Cu(NO3)2 contains how many O atoms? (Avagadros number)

Answer 1

Each molecule of copper (II) nitrate contains 6 atoms of Oxygen. One mole of any substance contains 6.02*10²³ structural units. So, there will be 6 times more Oxygen atoms, than we have copper (II) nitrate molecules:

$$N(O)=6*6.02*10^{23}=36.12*10^{23}=3.61210^{24} atoms$$

where N - number of atoms.

Answer: one mole of copper (II) nitrate contains 3.612*10²⁴ Oxygen atoms.