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JEE Main20266 April 2026Evening ShiftChemistrySome Basic Concepts of ChemistryActual

Which of the following contain the same number of atoms ? (Given : Molar mass in g mol ⁻¹ of H, He, O and S are 1, 4, 16 and 32 respectively) A. 2 g of O₂ gas B. 4 g of SO₂ gas C. 1400 mL of O₂ at STP D. 0.05 L of He at STP E. 0.0625 mol of H₂ gas Choose the correct answer from the options given below :

Options

  1. AA and B only
  2. BB and C only
  3. CC and D only
  4. DA, C and E only

Correct answer

D. A, C and E only

Step-by-step solution

Number of atoms is calculated as the product of the number of moles, atomicity, and Avogadro's number ( N_A ). For A: Moles of O₂ = 2 32 = 1 16 mol. Atomicity of O₂ is 2 . Number of atoms = 1 16 2 N_A = 1 8 N_A For B: Moles of SO₂ = 4 64 = 1 16 mol. Atomicity of SO₂ is 3 . Number of atoms = 1 16 3 N_A = 3 16 N_A For C: Moles of O₂ at STP = 1400 22400 = 1 16 mol. Atomicity of O₂ is 2 . Number of atoms = 1 16 2 N_A = 1 8 N_A For D: Moles of He at STP = 0.05 22.4 = 1 448 mol. Atomicity of He is 1 . Number of atoms = 1

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