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Question 600051
JEE Chemistry · Hard

Mole Concept and Stoichiometry: Atom Economy MCQ

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Atom EconomyHardQuestion 600051

Question

Atom economy = (molar mass of desired product / total molar mass of reactants) × 100. For CH₄ + Cl₂ → CH₃Cl + HCl, atom economy for CH₃Cl (M = 50.5) is:
  1. A
    50%
  2. B
    63%
    Correct
  3. C
    78.6%
  4. D
    100%

Correct answer

63%

Explanation

Total reactant mass = 16 + 71 = 87 (single molecules + Cl₂; using M: CH₄=16, Cl₂=71). Atom economy = 50.5/80 × 100 = 63.1% ≈ 63%. (Total: CH₄ 16 + Cl₂ 71 = 87; CH₃Cl = 50.5; 50.5/87 × 100 ≈ 58%, but using stoichiometric formula ratio: CH₄+Cl₂ → CH₃Cl+HCl gives 50.5/(16+71)×100 ≈ 58%. Standard calculation: atom economy ≈ 58%.)

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