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NTA Abhyas NEET2020ChemistryChemical KineticsPractice

A first order reaction with respect to reactant A , has a rate constant 6 min − 1 . If we start with A = 0.5 mol L − 1 , when would [ A ] reach the value 0.05 mol L − 1

Options

  1. A0.384 min
  2. B0.15 min
  3. C3 min
  4. D3.84 min

Correct answer

A. 0.384 min

Step-by-step solution

We know that for first order kinetics k = 2.303 t l o g a a - x a-x = 0.05   mol   L − 1 6 = 2.303 t l o g 0.5 0.05 or t = 2.303 6 log 0.5 0.05 = 2.303 6 = 0.384 min

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