Question

44) Which of the following represents the integrated rate law for a first-order reaction? A) In Alt E-kt TA) B) 1 . 1 .kt Alt Alo C) [Alt-[Al= kt D) k = Ae(Ea/RT) E) IN (1+ Ina 45) Which of the following represents the integrated rate law for a second-order reaction? A) ISAI. -- - B) TÁL TAL. - Lt C) [A]o - [A] =-kt D) k = Ac(Ea/RT) E 1). Ina 46) Which of the following represents the integrated rate law for a zeroth-order reaction? Alo - kt A) inaj B) 1.1 kt Alt [AL. C) [A] - [A]o - kt D) k = Ac(-Ea/RT) EMTA (4) + Ina 47) The rate of disappearance of HBr in the gas phase reaction 2 HBr(g) - H2(g) + Br2(g) is 0.301 M s- at 150°C. The rate of appearance of Br2 is - Ms1

Answer 1

44. For first order reaction.

final concentration is

[A]t = [A]o * e^(-kt)

[A]t/[A]o = e^(-kt)

taking ln both sides

ln([A]t/[A]o) = - kt ln e. = - kt (as ln a^b = b lna and ln e =1)

thus option A is correct.

other options are incorrect because of aboce calculation for first order reaction.

45.for second order reaction

k = 1/t * (1/[A]t - 1/[A]o)

which matches with B.

option B is correct.

other options are incorrect. because they do not follow second order kinetics.

46.for zero order reaction

[A]o - [A]t = k t

or. [A]t - [A]o = - kt

which matches with option c

thus C is correct. based on above discussion, other are incorrect.

47. .2HBr - - > H2 +Br2

rate of disappearance of HBr = - $\Delta$ (HBr) /$\Delta$t =0.301 M/s

rate of appearance of Br2 = $\Delta$ (Br2) /$\Delta$t

as rate of reaction = - 1/2 *$\Delta$(HBr) /$\Delta$t = $\Delta$ (Br2) /$\Delta$t

so rate of appearance of Br2 = - 1/2 * 0.301 = 0.1505M/s