NEET Exam  >  NEET Questions  >  A first order reaction takes 69.3 minutes for... Start Learning for Free
A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.?
Most Upvoted Answer
A first order reaction takes 69.3 minutes for 50% completion. Time in ...
Calculation of Time to Complete 80% of Reaction


Given:


  • First order reaction

  • 50% completion time = 69.3 minutes



To find: Time to complete 80% of the reaction


Formula Used

For a first order reaction, the time taken for a given percentage of completion can be calculated using the following formula:

t = (0.693/k) x log10 (A0/A)

where:


  • t = time taken for percentage completion

  • k = rate constant

  • A0 = initial concentration of reactant

  • A = concentration of reactant at time t



Calculation

Let's first calculate the rate constant (k) using the given information:

t1/2 = 69.3 minutes (given)

Using the formula:

t1/2 = (0.693/k)

k = 0.693/t1/2 = 0.693/69.3 = 0.01 min-1


Now, let's use the formula to calculate the time taken for 80% completion:

t = (0.693/k) x log10 (A0/A)

Let's assume the initial concentration of reactant (A0) is 1. Therefore, the concentration of reactant at 50% completion (A) would be 0.5.

Using the formula:

t = (0.693/0.01) x log10 (1/0.5)

t = 46.1 minutes


Answer

The time taken to complete 80% of the reaction is 46.1 minutes.


Explanation

Given that the reaction is a first order reaction, we can use the formula to calculate the time taken for a given percentage of completion. In this case, we were given the time taken for 50% completion and we used this information to calculate the rate constant (k). Once we had the value of k, we used the formula again to calculate the time taken for 80% completion. We assumed an initial concentration of 1 for simplicity. The final answer was 46.1 minutes.
Attention NEET Students!
To make sure you are not studying endlessly, EduRev has designed NEET study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in NEET.
Explore Courses for NEET exam

Top Courses for NEET

A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.?
Question Description
A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.?.
Solutions for A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? in English & in Hindi are available as part of our courses for NEET. Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free.
Here you can find the meaning of A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? defined & explained in the simplest way possible. Besides giving the explanation of A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.?, a detailed solution for A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? has been provided alongside types of A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? theory, EduRev gives you an ample number of questions to practice A first order reaction takes 69.3 minutes for 50% completion. Time in minutes to complete 80% of reaction.? tests, examples and also practice NEET tests.
Explore Courses for NEET exam

Top Courses for NEET

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev