Question

Number of $Fe$ atoms in 100 g haemoglobin if it contains 0.33% $Fe$.

(Atomic mass of $Fe=56$)

• A. $0.035\times {10}^{23}$
• B. $35$
• C. $3.5\times {10}^{23}$
• D. $7\times {10}^8$

Answer 1

The correct option is

A

$0.035\times {10}^{23}$

Mass of hemoglobin = 100 g

Mass of iron atoms $=\left(\frac{0.33}{100}\right)\times 100=0.33g$

56 g of iron contains = 1 mole of iron or $6.033\times {10}^{23}$ atoms

$0.33g$ of iron contains $=moles=\frac{0.33}{56}=5.89\times {10}^{-3}$

$No.ofatoms=5.89\times {10}^{-3}\times 6.023\times {10}^{23}$ = 0.035× ${10}^{23}$