Question

Hemoglobin contains $0.34 \%$ of iron by mass. The number of $Fe$ atoms in $3.3\, g$ of hemoglobin is : (Given : Atomic mass of $Fe$ is $56\, u , N _{ A }$ in $6.022 \times 10^{23} mol ^{-1}$ )

• A. $1.21 \times 10^5$
• B. $12.0 \times 10^{16}$
• C. $1.21 \times 10^{20}$
• D. $3.4 \times 10^{22}$

Answer 1

Answer: (C)

No. of Fe atoms $=\frac{0.34}{100} \times \frac{3.3}{56} \times 6.022 \times 10^{23} $
$=1.206 \times 10^{20}$