Question

The haemoglobin from the red blood corpuscles of most mammals contains approximately 0.33 % of iron by weight. The molecular weight of haemoglobin is 67,200. The number of iron atoms in each molecule of haemoglobin is:

(Atomic weight of iron = 56)

• A. 2
• B. 3
• C. 4
• D. 5

Answer 1

The correct option is C 4

Mass of iron present in one molecule of haemoglobin $=\frac{.33}{100}\times 67200=221.76$ g

Atomic weight of iron $=56$ g

$\therefore$ number of iron atoms present in one molecule of haemoglobin $=\frac{221.76}{56}=3.96\approx 4$.