MHT CET202120 Sep 2021Evening ShiftChemistryChemical KineticsActual
Half-life for a first order reaction is 6.93 hour. What is the time required for 80 % completion of the reaction?
Options
- A12 hours
- B18 hours
- C6 hours
- D16 hours
Correct answer
D. 16 hours
Step-by-step solution
For first order reaction, k = 0.693 t _ 1 2 = 0.693 6.93 =0.1 hour ⁻¹ Here, [ A ]₀=100,[ ~A ]_ t =100-80=20 aligned & Now, k = 2.303 t ₁₀ [ A ]₀ [ ~A ]_ t & t = 2.303 0.1 ₁₀ 100 20 =23.03 ₁₀ 5=23.03 0.699 & =16.10 hours. aligned