Question

For a first-order reaction, the half-life is constant. It depends only on the rate constant k k and not on the reactant concentration. It is expressed as t1/2=0.693k t 1 / 2 = 0.693 k For a second-order reaction, the half-life depends on the rate constant and the concentration of the reactant and so is expressed as t1/2=1k[A]0. A certain first-order reaction (A→products A → p r o d u c t s ) has a rate constant of 9.30×10−3 s−1 s − 1 at 45 ∘C ∘ C .

How many minutes does it take for the concentration of the reactant, [A] [ A ] , to drop to 6.25% % of the original concentration?

A certain second-order reaction (B→products B → p r o d u c t s ) has a rate constant of 1.95×10−3 M−1⋅s−1 M − 1 ⋅ s − 1 at 27 ∘C ∘ C and an initial half-life of 252 s s . What is the concentration of the reactant B B after one half-life?

Answer 1

0 Integrated rate equation for first order reaction - 20 t ln [A]. [A]o Initial conc [As fined conc karate constant to time k= 9.30x10 3 st 100 [AJ 6.25*[A) tr 1 lu te 9.30x/03 [Ato 0.0625 [A]. to I x2.77 9.30x10 3 298. I see I see I nun t. 298.1 - 4.96 sec for second Integrated deate Exration order reaction, I - Rt + 1 TAJ

intial cone half life is time when deduces to half. [A] - [ATO 2 [AI 141. Pago ex the in 2.952/53 x 252 [AJ 2.035= 2.04 m