Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202520 Apr 2025Morning ShiftChemistryChemical KineticsActual

The rate constant for a first order reaction is 0.58 ~s ⁻¹ at 300 K and 0.026 ~s ⁻¹ at 290 K . What is the energy of activation? ( R =8.314 ~J ~K ⁻¹ ~mol ⁻¹ )

Options

  1. A124 48 ~kJ
  2. B224 55 ~kJ
  3. C348 18 ~kJ
  4. D513 21 ~kJ

Correct answer

B. 224 55 ~kJ

Step-by-step solution

The activation energy E_a is determined using the Arrhenius equation for two temperatures and their corresponding rate constants: ( k₂ k₁ ) = E_a R ( 1 T₁ - 1 T₂ ) Given k₁ = 0.026~ s ⁻¹ at T₁ = 290~ K and k₂ = 0.58~ s ⁻¹ at T₂ = 300~ K , with R = 8.314~ J~K⁻¹~mol⁻¹ , the ratio k₂ k₁ 22.30769 and (22.30769) 3.1048 . The temperature term evaluates to 1 290 - 1 300 = 10 87000 0.0001149425~ K ⁻¹ . Substituting yields 3.1048 = E_a 8.314 0.0001149425 , giving E_a = 3.1048 8.314 0.0001149425 224627.9~ J~mol⁻¹ . Convertin

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