If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by [2019]

STUDY MATERIALS
COURSES
MORE
SUCCESS STORY
ADMISSION
STORE

Back

JEE ADVANCE

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

JEE MAIN

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

NEET

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

BITSAT

CLASS XI - XII

CLASS XI - XII

CBSE BOARD

CLASS IX

CLASS X

CLASS XI

CLASS XII

CLASS VI

CLASS VII

CLASS VIII

UP BOARD

CLASS IX
CLASS X
CLASS XI
CLASS XII

CLASS IX

CLASS X

CLASS XI

CLASS XII

CUET

CRASH COURSE

CRASH COURSE

Courses

CLASSROOM COURSES
ONLINE COURSES

ONLINE COURSES

More

Solution

Q.
If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by [2019]

1 $t = 2.303 / k$

2 $t = 0.693 / k$

3 $t = 6.909 / k$

4 $t = 4.606 / k$

Ans.
(4)

For $1^{st}$ order reaction,

$t = \frac{2.303}{k} \log \frac{a}{a - x} = \frac{2.303}{k} \log \frac{100}{100 - 99}$

$= \frac{2.303}{k} \log 10^{2} = \frac{2.303}{k} \times 2 \times \log 10 = \frac{4.606}{k}$

Want Us to Email you About Special Offers & Updates?