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Manipal MET2010ChemistryChemical Kinetics

For a first order reaction, the concentration changes from 0.8 to 0.4 in 15 min . The time taken for the concentration to change from 0.1 M to 0.025 M is

Options

  1. A30 min
  2. B15 min
  3. C7.5 min
  4. D60 min

Correct answer

A. 30 min

Step-by-step solution

aligned & T₅₀=15 ~min & k= 2.303 2 T₅₀ = 2.303 2 15 aligned aligned a & =0.1 M (a-x) & =0.025 M aligned For first order reaction, k= 2.303 t ( a a-x ) aligned 2.303 2 15 & = 2 2.303 t 0.1 0.025 & = 2.303 t 4 aligned 2.303 2 15 = 2 2.303 2 t t=30 ~min

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