How many hydrogen atoms are contained in 1.50 g of glucose

How many hydrogen atoms are contained in 1.50 g of glucose (C₆H₁₂O₆)?

3.01 × 10²²
1.20 × 10²³
2.40 × 10²³
6.02 × 10²²
This question was previously asked in
UPSC CDS-2 – 2017
The correct option is D) 6.02 × 10²² .
To find the number of hydrogen atoms, we first need to calculate the number of moles of glucose in 1.50 g. The molar mass of glucose (C₆H₁₂O₆) is (6 × 12.01) + (12 × 1.008) + (6 × 16.00) ≈ 180.16 g/mol (using rounded values C=12, H=1, O=16 gives 180 g/mol).
Number of moles of glucose = mass / molar mass = 1.50 g / 180 g/mol ≈ 0.00833 moles.
One molecule of glucose (C₆H₁₂O₆) contains 12 hydrogen atoms. Therefore, one mole of glucose contains 12 moles of hydrogen atoms.
Number of moles of hydrogen atoms = 0.00833 mol glucose × 12 mol H atoms/mol glucose = 0.1 moles of hydrogen atoms.
Number of hydrogen atoms = moles of H atoms × Avogadro’s number (6.022 × 10²³ atoms/mol) = 0.1 mol × 6.022 × 10²³ atoms/mol ≈ 0.6022 × 10²³ atoms = 6.022 × 10²² atoms.
Avogadro’s number is the number of constituent particles (atoms, molecules, ions, etc.) that are contained in one mole of a substance, approximately 6.022 × 10²³. The formula weight calculation needs to consider the number of atoms of each element in the molecular formula.