Question

Number of Fe atoms in 100 g hemoglobin if it contains 0.33 percent iron. (Atomic mass of Fe = 56)
a.) $0.035\text{x}{{10}^{23}}$
b.) 35
c.) $3.5\text{x}{{10}^{23}}$
d.) $\text{7x}{{10}^{8}}$

Answer 1

In order to solve this question, use mole concept. We have been provided with a percentage of iron in hemoglobin. Using that, find the weight of iron in hemoglobin, then calculate the number of atoms.

Complete step by step solution:
Given, weight of hemoglobin = 100 g
Since Hemoglobin contains 0.33 $$ of Fe,
Therefore, weight of Fe in Hemoglobin = 0.33 $$ of 100 g = (0.33/100) x 100 = 0.33 g
To calculate the number of moles –
Moles = weight / molar mass
Weight = 0.33 g
Molar mass/ Atomic weight of Fe = 56 g/mol
Therefore, number of moles = 0.33/ 56 = 0.00589 mol
Now, we need to calculate the number of atoms.
Since number of atoms = number of moles x Avogadro’s number
Therefore, number of atoms = 0.00589 x 6.023 x ${{10}^{23}}$
Number of atoms = $0.035\text{x}{{10}^{23}}$

Therefore, the answer is – option (a).

Additional Information: Hemoglobin has a structure made up of four pyrrole rings. Each hemoglobin structure contains iron as the central metal atom.

Note: Hemoglobin is a metalloprotein present in red blood cells in our body. The main function of hemoglobin is to carry oxygen from the lungs to the body's tissues and to return carbon dioxide from tissues back to the lungs.