Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202611 April 2026Evening ShiftChemistryChemical KineticsActual

Half life period of a first order reaction is 1386 seconds. The rate constant of the reaction is

Options

  1. A5.5 10⁻² s⁻¹
  2. B0.5 10⁻³ s⁻¹
  3. C5 10⁻² s⁻¹
  4. D5 10⁻³ s⁻¹

Correct answer

B. 0.5 10⁻³ s⁻¹

Step-by-step solution

For a first order reaction, the rate constant k is related to the half life period t_ 1/2 by the formula: k = 0.693 t_ 1/2 Given t_ 1/2 = 1386 s , substituting this value: k = 0.693 1386 k = 693 10⁻³ 2 693 k = 0.5 10⁻³ s ⁻¹ Answer: 0.5 10⁻³ s⁻¹

Practice Chemical Kinetics on Quantrex Academy →

More from Chemical Kinetics

When the concentration of the reactant in a given reaction is halved and if the rate of reaction is halved, the order of the reaction is: 2026A first order reaction is 50%complete in 30 minutes at 300 K and in 10 minutes at 320 K. The activation energy of the reaction (E_a ) is: [R=8.314 J K ⁻¹ mol ⁻¹ ; log 2 = 0.3010; l 2026In the synthesis of NH₃ from H₂ and N₂ , if 6 10⁻² mole of hydrogen disappears in 10 minutes, the number of moles of NH₃ formed in 0.3 minutes is: 2026The initial pressure of the system before decomposition for a first order gas phase reaction A_ (g) B_ (g) + C_ (g) was P_i . After lapse of time 't', total pressure of the system 2026Which of the following factors is altered by the addition of a catalyst during a chemical reaction? 2026The rate constants for two different reactions, k₁ and k₂ are 10¹⁶ e^ -2000/T and 10¹⁵ e^ -1000/T respectively. The temperature at which k₁ = k₂ is 202660% of a first order reaction was completed in 60 min, then 50% of the same reaction can be completed in: [log 4 = 0.60, log 5=0.69] 2026Identify the correct values to be plotted in the graph, the slope of which can be used to determine the activation energy of a reaction. 2026 Full Chemical Kinetics list All MHT CET PYQs