Chemistry - Mole Concept Question with Solution | TestHub

Mass of haemoglobin = $3.3\mathrm{g}$

Mass of iron atoms = $\frac{0.34}{100}\times 3.3=0.01122\mathrm{g}$

$56 \mathrm{g}$of iron contains = $1$ mole of iron or $6.023 \times {10}^{23}$ atoms

Number of moles of atoms=$\frac{\mathrm{Mass} }{\mathrm{atomic} \mathrm{mass}}$

Number of moles of $0.01122\mathrm{g}$ of iron is

Number of moles = $\frac{0.01122\mathrm{g}}{56\mathrm{g}}=0.00020$ moles

Number of atoms =Number of moles $\times$avogadro number

No. of $\mathrm{Fe}$ atoms

 $$\begin{gathered} =0.00020\times 6.022\times {10}^{23} \\ =1.2046 \times {10}^{20} \end{gathered}$$