Chemistry Exam  >  Chemistry Questions  >  A first-order reaction is 50 percent complete... Start Learning for Free
A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.

  • a)
    30 minutes

  • b)
    60 minutes

  • c)
    90 minutes

  • d)
    120 minutes

Correct answer is option 'C'. Can you explain this answer?
Most Upvoted Answer
A first-order reaction is 50 percent complete in 30 minutes. Calculate...
To solve this problem, we can use the first-order reaction equation:

ln(No/N) = kt

Where:
No = initial concentration of the reactant
N = concentration of the reactant at a given time
k = rate constant
t = time

We are given that the reaction is 50 percent complete in 30 minutes. This means that N/No = 0.5. Substituting this into the equation, we get:

ln(0.5) = k * 30

Solving for k, we find:

k = ln(0.5)/30

Now we need to find the time taken for completion of 87.5 percent of the reaction. This means that N/No = 0.125. Substituting this into the equation and solving for t, we get:

ln(0.125) = (ln(0.5)/30) * t

Simplifying this equation, we find:

ln(0.125) = ln(0.5)/30 * t

Taking the exponential of both sides, we get:

0.125 = e^(ln(0.5)/30 * t)

Simplifying further, we find:

0.125 = (0.5)^(1/30 * t)

Taking the logarithm of both sides, we get:

log(0.125) = log((0.5)^(1/30 * t))

Using the logarithmic identity log(a^b) = b * log(a), we can rewrite the equation as:

log(0.125) = (1/30 * t) * log(0.5)

Simplifying further, we find:

log(0.125) = (1/30 * t) * (-0.301)

Solving for t, we find:

t = (log(0.125) / (-0.301)) * 30

Calculating this expression, we find that t is approximately 89.9 minutes. Thus, the time taken for completion of 87.5 percent of the reaction is approximately 90 minutes, which corresponds to option c.
Free Test
Community Answer
A first-order reaction is 50 percent complete in 30 minutes. Calculate...
Reaction is 50 percent complete in 30 minutes. Hence, t1/2 = 30 minutes
75 percent of the reaction is completed in two half-lives. Hence, t = 2 × 30 = 60 minutes
87.5 percent of the reaction is completed in three half-lives. Hence, t = 3 × 30 = 90 minutes.
Explore Courses for Chemistry exam
A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer?
Question Description
A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? for Chemistry 2024 is part of Chemistry preparation. The Question and answers have been prepared according to the Chemistry exam syllabus. Information about A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Chemistry 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer?.
Solutions for A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for Chemistry. Download more important topics, notes, lectures and mock test series for Chemistry Exam by signing up for free.
Here you can find the meaning of A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A first-order reaction is 50 percent complete in 30 minutes. Calculate the time taken for completion of 87.5 percent of the reaction.a)30 minutesb)60 minutesc)90 minutesd)120 minutesCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice Chemistry tests.
Explore Courses for Chemistry exam
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