KCET2015ChemistryChemical Kinetics
In a first order reaction, the concentration of the reactant is reduced to ( 12.5 % ) in one hour. When was it half completed?
Options
- A( 3 hr )
- B( 20 ~min )
- C( 30 ~min )
- D( 15 ~min )
Correct answer
B. ( 20 ~min )
Step-by-step solution
For first order reaction [ array l k= 2.303 t [A]₀ [A] = 2.303 60 [100] [12.5] =0.0346 ~min ⁻¹ t_ 1 / 2 = 0.693 k = 0.693 0.0346 =20 ~min array ]