Question

Number of Fe atoms in 100g haemoglobin is our contains 0.33% Fe

Answer 1

Weight of Hemoglobin = 100g
∵ Hemoglobin contains 0.33% of Fe
∴ weight of Fe in hemoglobin = 0.33% of 100g
= 0.33/100 × 100 = 0.33g

Atomic weight of Fe = 56g/mol
Weight of Fe = 0.33g
∴ number of mole = weight of Fe/atomic weight of Fe
= 0.33/56 = 0.00589

∵ number of atoms = number of mole × Avogadro's number
∴ number of atoms of Fe = 0.00589 × 6.023 × 10²³
= 0.0354 × 10²³
= 3.54 × 10²¹

Hence, answer is 3.54 × 10²¹

Answer 2

Given weight of hemoglobin = 100g

weight of iron present in 100g hemoglobin=0.33% =(0.33/100)x100 =0.33g

Atomic weight of Fe=56u

Molar mass of Fe=56g

As we know that 1mole (56g of Fe ) contains 6.023 x 10²³ atoms

∴
56g of Fe Contains ------------>6.023 x 10²³ atoms
0.33 g of Fe contains ----------->?
= (0.33 x6.023 x 10²³ atoms)/56
=3.5492 x 10 ²¹ atoms.

∴0.33g of Fe contains 3.5492 x 10 ²¹ atoms.