Question:
A first order reaction has a rate constant of $6.93\times10^{-4}\ \text{s}^{-1}$ at $300\ \text{K}$. What is the half-life period of the reaction in seconds at the same temperature?
A first order reaction has a rate constant of $6.93\times10^{-4}\ \text{s}^{-1}$ at $300\ \text{K}$. What is the half-life period of the reaction in seconds at the same temperature?
Show Hint
$0.693$ is approximately the natural log of 2 ($\ln 2$).
Updated On: Apr 28, 2026
- 693
- 6930
- 10000
- 1000
- 500
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Step 1: Concept
For a first-order reaction, $t_{1/2} = \frac{0.693}{k}$.
Step 2: Meaning
The half-life is independent of the initial concentration.
Step 3: Analysis
$t_{1/2} = \frac{0.693}{6.93 \times 10^{-4}} = \frac{0.693}{0.000693} = 1000$ seconds.
Step 4: Conclusion
The half-life period is 1000 seconds. Final Answer: (D)
For a first-order reaction, $t_{1/2} = \frac{0.693}{k}$.
Step 2: Meaning
The half-life is independent of the initial concentration.
Step 3: Analysis
$t_{1/2} = \frac{0.693}{6.93 \times 10^{-4}} = \frac{0.693}{0.000693} = 1000$ seconds.
Step 4: Conclusion
The half-life period is 1000 seconds. Final Answer: (D)
Was this answer helpful?
0
0
Top KEAM Chemistry Questions
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
- $4\, g$ of copper was dissolved in concentrated nitric acid. The copper nitrate solution on strong heating gave $5\, g$ of its oxide. The equivalent weight of copper is :
- Green chemistry deals with
- Neopentyl bromide undergoes dehydrohalogenation to give alkenes even though it has no $\beta$- hydrogen. This is due to
- Plot of $ log\text{ }x/m $ against log $p$ is a straight line inclined at an angle of $ 45{}^\circ $ . When the pressure is $ 0.5 \,arm $ and Freundlich parameter. $ k $ is $ 10 $ , the amount of solute adsorbed per gram of adsorbent will be $ (log\text{ }5=0.6990) $
View More Questions
Top KEAM Half life Questions
- What is the half life period of the first order reaction whose rate constant is \(2.31 \times 10^{- 1} \mathrm{~s}^{- 1}\)
- The first order rate constant for the decomposition of \( \text{N}_2\text{O}_5 \) is \( 6.93 \times 10^{-4}\, \text{sec}^{-1} \). Its half-life period is
- A first order reaction is 75% completed in 1000 s at 300 K. What is its half-life period at 300 K?
- The rate constant of a first order reaction is \(231\times10^{-5}\ s^{-1}\). How long will 4 g of this reactant reduce to 2 g?
Top KEAM Questions
- i.$\quad$ They help in respiration ii.$\quad$ They help in cell wall formation iii.$\quad$ They help in DNA replication iv. $\quad$They increase surface area of plasma membrane Which of the following prokaryotic structures has all the above roles?
- A body oscillates with SHM according to the equation (in SI units), $x = 5 cos \left(2\pi t +\frac{\pi}{4}\right) .$ Its instantaneous displacement at $t = 1$ second is
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
Kepler's second law (law of areas) of planetary motion leads to law of conservation of
- If $\int e^{2x}f' \left(x\right)dx =g \left(x\right)$, then $ \int\left(e^{2x}f\left(x\right) + e^{2x} f' \left(x\right)\right)dx =$
View More Questions