Question-14 Calculate the time in seconds required to reduce the concentration of reactant to half of initial concentration for first order reaction if rate constant is 1.386\times10^{-3}\ s^{-1}
(A) 140 s
(B) 290 s
(C) 390 s
(D) 500 s
Answer : (D)
Explanation:
For first order reaction, half life period is independent of initial concentration.
t_{1/2} = \frac{0.693}{k} = \frac{0.693}{1.386 \times 10^{-3}} = 500 s