Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK2025ChemistryChemical KineticsActual

During a chemical reaction X Y , the rates of reaction starting with initial concentrations of X as 4.0 10⁻³ M and 2.0 10⁻³ M are 4.8 10⁻⁴ ~mol ~L ⁻¹ / s and 1.2 10⁻⁴ ~mol ~L ⁻¹ / s respectively. What is the order of reaction with respect to X ?

Options

  1. A1.5
  2. B2
  3. C1
  4. D3

Correct answer

B. 2

Step-by-step solution

The rate law for the reaction X Y is given by r = k[X]^ n , where n is the order of the reaction. For the first condition: 4.8 10⁻⁴ = k(4.0 10⁻³)^ n (Equation 1) For the second condition: 1.2 10⁻⁴ = k(2.0 10⁻³)^ n (Equation 2) Dividing Equation 1 by Equation 2: 4.8 10⁻⁴ 1.2 10⁻⁴ = k(4.0 10⁻³)^ n k(2.0 10⁻³)^ n 4 = ( 4.0 10⁻³ 2.0 10⁻³ )^ n 4 = (2)^ n Since 4 = 2² , we have n = 2 . Answer: 2

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 COMEDK PYQs