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NEET2026ChemistrySome Basic Concepts of ChemistryActual

The number of hydrogen atoms present in 5.4 g of urea is : (Given : Molar mass of urea : 60 g mol ⁻¹ , N_A : 6.022 10²³ particles mol ⁻¹ )

Options

  1. A1.084 10²³
  2. B1.084 10²²
  3. C2.168 10²²
  4. D2.168 10²³

Correct answer

D. 2.168 10²³

Step-by-step solution

The chemical formula of urea is NH₂CONH₂ . Number of moles of urea = 5.4 60 = 0.09 mol. One molecule of urea contains 4 hydrogen atoms. Number of moles of hydrogen atoms = 4 0.09 = 0.36 mol. Total number of hydrogen atoms = 0.36 N_A = 0.36 6.022 10²³ = 2.16792 10²³ 2.168 10²³ . Answer: 2.168 10²³

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