Question
Chemistry Question on Chemical Kinetics
The first order integrated rate equation is
A
k=tx
B
k=t2.303loga−xa
C
k=t1lna−xa
D
k=t1a(a−x)a
Answer
k=t1lna−xa
Explanation
Solution
For first order, rate =dtd[R]=k[R] or [R]d[R]=kdt...(i) On integrating E (i) ∫[R]d[R]=k∫dt ln [R] = -kt + C \hspace25mm ... (ii) At t = O,[R] = [R0] [where, R = final concentration, i.e., a - x and R0 is the initial concentration, i.e., a.] ln[R0]=C On putting the value of C in E (ii), we get ln[R]=−kt+ln[R0] −kt=ln[R]−ln[R0] kt=ln[R0]−ln[R] or k=t1ln[R][R0] or k=t1lna−xa