Answer :
Answer: The mass of iron (II) oxide that contains a million iron atoms is [tex]2.6\times 10^{-17}g[/tex]
Explanation:
We are given:
Number of iron atoms = A million = [tex]1.0\times 10^6[/tex]
The chemical formula of the given compound is [tex]Fe_2O_3[/tex]
It is formed by the combination of 2 iron atoms and 3 oxygen atoms.
According to mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of particles
1 mole of iron (II) oxide will contain = [tex](2\times 6.022\times 10^{23})=1.2044\times 10^{24}[/tex] number of iron atoms
We know that:
Molar mass of iron (II) oxide = 159.7 g/mol
Applying unitary method:
For [tex]1.2044\times 10^{24}[/tex] number of iron atoms, the mass of iron (II) oxide is 159.7 g
So, for [tex]1.0\times 10^6[/tex] number of iron atoms, the mass of iron (II) oxide will be [tex]\frac{159.7}{1.2044\times 10^{24}}\times 1.0\times 10^6=2.6\times 10^{-17}g[/tex]
Hence, the mass of iron (II) oxide that contains a million iron atoms is [tex]2.6\times 10^{-17}g[/tex]