Question

The molecular weight of hemoglobin is about $65,000g/L$. Hemoglobin contains 0.35% Fe by mass. How many iron atoms are there in a hemoglobin molecule?

Answer 1

To find mass of $Fe=\frac{35}{100}\times 65000=22750g$

$56$ $g$ has $6.023\times {10}^{23}$ atoms

$22750$ $g$ has $X$ atoms

$X=\frac{22750}{56}\times 6.022\times {10}^{23}=24.46\times {10}^{75}$ atoms of $Fe$