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NEETChemistrySome Basic Concepts of Chemistry

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): 1 g of oxygen gas ( O₂ ) contains a greater number of atoms than 1 g of hydrogen gas ( H₂ ). Reason (R): For a given mass of an elemental gas, the total number of atoms is inversely proportional to its atomic mass. In the light of the above statements, choose the most appropriate answer from the op

Options

  1. ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A).
  2. BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A).
  3. CAssertion (A) is correct but Reason (R) is incorrect.
  4. DAssertion (A) is incorrect but Reason (R) is correct.

Correct answer

D. Assertion (A) is incorrect but Reason (R) is correct.

Step-by-step solution

Assertion (A) is incorrect: The number of moles of O₂ in 1 g is 1 32 . Since each O₂ molecule has 2 atoms, the total number of oxygen atoms is 1 32 2 N_A = N_A 16 . The number of moles of H₂ in 1 g is 1 2 . The total number of hydrogen atoms is 1 2 2 N_A = N_A . Thus, 1 g of H₂ contains more atoms than 1 g of O₂ . Reason (R) is correct: For a given mass m of an elemental gas with atomicity x and atomic mass A , the molar mass is x A . The total number of atoms is m x A x N_A = m A N_A . Therefore, for a constant ma

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