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COMEDK202510 May 2025Evening ShiftChemistryChemical KineticsActual

(i) and (ii) are 2 chemical reactions carried out at TK with identical pre-exponential factors. (i). X Y + W with k₁ as rate constant. (ii). X Z + W with k₂ as rate constant. The Activation energy for reaction (ii) is 3 times that of reaction (i). What is the expression for k₁ ?

Options

  1. Ak₁=-2 k₂ e^ 2 E a₁ / R T
  2. Bk₁= ^ k₂ / 2 e^ -E a₁ / R T
  3. Ck₁=k₂ e^ 2 E a₁ / R T
  4. Dk₁=2 k₂ e^ E a₁ / R T

Correct answer

C. k₁=k₂ e^ 2 E a₁ / R T

Step-by-step solution

Both reactions have identical pre-exponential factor A and E_ a2 = 3E_ a1 . k₁ = Ae^ -E_ a1 /RT and k₂ = Ae^ -3E_ a1 /RT k₁ k₂ = e^ (-E_ a1 +3E_ a1 )/RT = e^ 2E_ a1 /RT k₁ = k₂ e^ 2E_ a1 /RT

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