# A first order rea

Given:

Time for 25% decomposition = 20 minutes

First we need to calculate the value of rate constant. To calculate rate constant, we apply the formula for the first order reaction:

K = log

Where t is time,

a is the no. of moles per litre,

(a-x) is the concentration of a after time t

As, t = 20 minutes (given)

a = 100, x = 25

k = log

k = log

k = 0.0143 min-1

Now, t= ?, when reaction is 75% complete, i.e., x= 75

To calculate the time, we apply the same formula

K = log

Using formula, we write

t = log

As, k = 0.0143 min-1 (calculated above)

t = log

t = log

t = 96.96 minute

Thus, the time when 75% of the reaction will be completed is 96.96 minutes.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses
RELATED QUESTIONS :

Note: In the follChemistry - Exemplar

Which of the follChemistry - Exemplar