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99 Percentile Qs Bank for JEE MainChemistryChemical Kinetics

The energy of activation for an uncatalysed reaction is 100 kJ mol -1 . Presence of a catalyst lowers the energy of activation by 75%. The log 1 0 K 2 K 1 of the ratio of rate constant of catalysed and uncatalysed reactions at 27°C is? Assume the frequency factor is same for both reactions. (Given 2.303 × 8.314 = 19.147)

Options

  1. A13.05
  2. B26.10
  3. C6.52
  4. DNone of these

Correct answer

A. 13.05

Step-by-step solution

In absence of catalyst, K 1 = Ae - 1 0 0 / RT In presence of catalyst ; K 2 = Ae - 2 5 / RT ∴ K 2 K 1 = e 7 5 / RT ⇒ log e K 2 K 1 = 7 5 RT ⇒ log 1 0 K 2 K 1 = 7 5 2.303 × R × T ⇒ log 1 0 K 2 K 1 = 7 5 2.303 × 8.314 × 1 0 - 3 × 3 0 0 = 13.057

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