Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  •  For a first order reaction having initial concentration of reactant <img alt="A_0" sr

 For a first order reaction A \rightarrow B having initial concentration of reactant A_0  and rate constant 3.5 \mathrm{~min}^{-1}. If time taken to convert remaining reactant amount from \mathrm{A_0 \! \; to\; \frac{A_0}{2}} is 10 minutes, than what will be the time taken to convert remaining reactant amount from \frac{A_0}{4}\: to\: \frac{A_0}{8} ?

Option: 1

2.5 minutes


Option: 2

10.5 minutes


Option: 3

40.0 minutes


Option: 4

10.0 minutes


Answers (1)

best_answer

When reactant amount changes from \mathrm{A_0\; to \; \frac{A_0}{2}}, amount gets half, which means time taken is half life.

\Rightarrow t_{\frac{1}{2}}=10 minutes, similarly when reactant amount changes from \frac{A_0}{4}\: \; \text{to} \; \; \frac{A_0}{8}, again the reactant amount gets half, thus time taken will be equal to half life. This is because t_{\frac{1}{2}} of the first order reaction is independent of reactant amount/concentration.

Thus time taken to convert reactant amount from \mathrm{\frac{A_0}{4}\; to \; \frac{A_0}{8}} is also 10 minutes.

NOTE: For a first order reaction, if reactant is halved the time taken will be equal to half life of the reaction, as half life of first order reaction is independent of reactant amount.

Posted by

Sayak

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

BTech aspirant from north-east or UT? Apply for CSAB NEUT counselling 2025 today
anam-khan

JoSAA round 2 cut-off 2025 out; BTech closing ranks for top engineering courses at IITs
anam-khan

Goa Engineering Admission 2025: 1,415 eligible for BE seats; merit list on June 27

Latest Question