JEE Main 2022 — Chemistry Physical Chemistry

2022mcqeasy

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

Official previous-year question

Held on 26 Jul 2022 · Verified 6 Jul 2026.

Options

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

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Solution

Mass of haemoglobin = $3.3g$

Mass of iron atoms = $\frac{0.34}{100}\times 3.3=0.01122g$

$56g$ of iron contains = $1$ mole of iron or $6.023\times {10}^{23}$ atoms

Number of moles of atoms= $\frac{\mathrm{Mass}}{\mathrm{atomic}\mathrm{mass}}$

Number of moles of $0.01122g$ of iron is

Number of moles = $\frac{0.01122g}{56g}=0.00020$ moles

Number of atoms =Number of moles $\times$ avogadro number

No. of $\mathrm{Fe}$ atoms

$=0.00020\times 6.022\times {10}^{23} =1.2046\times {10}^{20}$

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JEE Main Physical Chemistry in other years

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JEE Main 2022 — Chemistry Physical Chemistry

2022mcqeasy

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

Official previous-year question

Held on 26 Jul 2022 · Verified 6 Jul 2026.

Options

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

Did you get this right?

Solution

Mass of haemoglobin = $3.3g$

Mass of iron atoms = $\frac{0.34}{100}\times 3.3=0.01122g$

$56g$ of iron contains = $1$ mole of iron or $6.023\times {10}^{23}$ atoms

Number of moles of atoms= $\frac{\mathrm{Mass}}{\mathrm{atomic}\mathrm{mass}}$

Number of moles of $0.01122g$ of iron is

Number of moles = $\frac{0.01122g}{56g}=0.00020$ moles

Number of atoms =Number of moles $\times$ avogadro number

No. of $\mathrm{Fe}$ atoms

$=0.00020\times 6.022\times {10}^{23} =1.2046\times {10}^{20}$

Your note

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

Work through every JEE Main Physical Chemistry PYQ, year by year.

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JEE Main 2022 — Chemistry Physical Chemistry

Options

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Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

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JEE Main 2022 — Chemistry Physical Chemistry

Options

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry