Question

The haemoglobin contains $0.33$% of iron by weight. Its molecular weight is $67200$. What is the number of iron atoms in each molecule (atomic weight of iron$=56$)?

• A. $2$
• B. $3$
• C. $4$
• D. $5$

Answer 1

The correct option is C $4$

Weight of iron present in $67200g$ of the haemoglobin $=\frac{0.33}{100}\times 67200=221.76g$

The atomic weight of iron $=56$

No. of iron atoms present in one molecules of haemoglobin $=\frac{221.76}{56}=3.96\approx 4$