MHT CET202016 Oct 2020Evening ShiftChemistryChemical KineticsActual
What is the value of rate constant of first order reaction, if it takes 15 minutes for consumption of 20 % of reactants?
Options
- A1 84 10⁻² ⁻¹
- B1 38 10⁻² ⁻¹
- C1 07 10⁻² ⁻¹
- D1 48 10⁻² ⁻¹
Correct answer
D. 1 48 10⁻² ⁻¹
Step-by-step solution
(B) [ A ]₀= Original amount of reactant =100[ A ]_ t = Reactant remaining unreacted =100-20=80 For first order reaction, aligned k &= 2.303 t ₁₀ [ A ]₀ [ ~A ]_ t k &= 2.303 15 ~min ₁₀ 100 80 =0.0148 ~min ⁻¹ k &=1.48 10⁻² ~min ⁻¹ aligned