MHT CET202526 Apr 2025Morning ShiftChemistryChemical KineticsActual
Rate of the reaction A + B product is 3.6 10⁻² ~mol~ dm ⁻³ ~s ⁻¹ and rate law is r = k [ A ][ B ]^2 . What is rate constant of the reaction if [ A ]=0 2 M and [ B ]=0 1 M ?
Options
- A10 ~mol ⁻² dm ^6 ~s ⁻¹
- B18 ~mol ⁻² dm ^6 ~s ⁻¹
- C24 ~mol ⁻² dm ^6 ~s ⁻¹
- D4.8 ~mol ⁻² dm ^6 ~s ⁻¹
Correct answer
B. 18 ~mol ⁻² dm ^6 ~s ⁻¹
Step-by-step solution
The rate law is given by r = k[A][B]^2 . Solving for the rate constant yields k = r [A][B]^2 . Substituting the values r = 3.6 10⁻² > mol > dm ⁻³ > s ⁻¹ , [A] = 0.2 > mol > dm ⁻³ , and [B] = 0.1 > mol > dm ⁻³ gives k = 3.6 10⁻² 0.2 (0.1)^2 = 3.6 10⁻² 0.2 0.01 = 3.6 10⁻² 2 10⁻³ = 1.8 10¹ = 18 > mol ⁻² > dm ^6 > s ⁻¹ . This corresponds to option B .