A first order reaction has the rate constant, k = 4 . 6 × 10 - 3 s - 1 . The number of correct statement/s from the following is/are Given: log 3 = 0 . 48 . A. Reaction completes in 1000 s . B. The re

Question

A first order reaction has the rate constant, $k = 4.6 \times 10^{- 3} s^{- 1}$ . The number of correct statement/s from the following is/are Given: $\log 3 = 0.48$ .

A. Reaction completes in $1000 s$ .
B. The reaction has a half-life of $500 s$ .
C. The time required for $10 %$ completion is 25 times the time required for 90% completion.
D. The degree of dissociation is equal to $(1 - e^{- kt})$ .
E. The rate and the rate constant have the same unit.

TestHub · Accepted Answer

For a first order reaction: t 1 2 = 0 . 693 k = 0 . 693 4 . 6 × 10 - 3 s - 1 = 150 . 65 s For a first order reaction, t 10 % = 1 K ln a a - x = 1 K ln 100 90 t 10 % = 2 . 303 K ( log 10 - log 9 ) t 10 % = 2 . 093 K × ( 0 . 04 ) Similarly t 90 % = 1 K ln 100 10 t 90 % = 2 . 303 K t 90 % t 10 % = 1 0 . 04 = 25 We know, e kt = a a - x a - x a = e - kt x = a 1 - e - kt α = x a = 1 - e - kt Thus, only option (D) is correct.

Chemistry - Chemical Kinetics Question with Solution | TestHub

Doubts & Discussion