MHT CET202013 Oct 2020Evening ShiftChemistryChemical KineticsActual
The half life of a first order reaction is 6.0 hour. How long will it take for the concentration of reactant to decrease from 0.4 M to 0 12 M ?
Options
- A30 36 ~h
- B10.42 ~h
- C4.25 ~h
- D9.51 ~h
Correct answer
B. 10.42 ~h
Step-by-step solution
For first order reaction, array l k= 0.693 t_ 1 / 2 = 0.693 6.0 h =0.1155 h⁻¹ Here, [A]₀=0.4 M,[A]_ t =0.12 M t= 2.303 k ₁₀ [A]₀ [A]₁ = 2.303 0.1155 h⁻¹ ₁₀ 0.4 0.12 = 2.303 0.1155 0.5224 t=10.42 h array