Respuesta :
The molecular formula of the compound is [tex]ZnCO_{3}[/tex], from the molecular formula it is clear that 1 mol of [tex]ZnCO_{3}[/tex] contains 3 mol of oxygen.
Also, in 1 mol there are [tex]6.023\times 10^{23}[/tex] atoms thus, 3 mol of oxygen will have [tex]18.069\times 10^{23}[/tex] atoms of oxygen.
Thus, there are [tex]18.069\times 10^{23}[/tex] atoms of oxygen present in 1 mol of [tex]ZnCO_{3}[/tex].
1 atom of oxygen will be there in [tex]3\times 6.023\times 10^{23}=5.53\times 10^{-25}[/tex] mol.
Number of oxygen atoms given is [tex]3.11\times 10^{22}[/tex] thus, this will be present in [tex]3.11\times 10^{22}\times 5.53\times 10^{-25} mol.=0.01721 mol[/tex] of [tex]ZnCO_{3}[/tex].
Molar mass of [tex]ZnCO_{3}[/tex] is 125.388 g/mol, thus, mass can be calculated as follows:
[tex]n=\frac{m}{M}[/tex]
Rearranging the above equation,
[tex]m=n\times M[/tex]
Putting the values,
[tex]m=(0.01721 mol)\times (125.388 g/mol)=2.16 g[/tex]
Therefore, the mass of [tex]ZnCO_{3}[/tex] is 2.16 g.
