First Order Half-life
Half-life (t1/2) of a first-order reaction depends on:
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About This Question
- Subject
- chemistry
- Chapter
- chemical kinetics
- Topic
- first order half-life
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
Rate constant only
- Integrated Rate Law: k=t2.303log[A][A]0.
- Definition of Half-life: Time after which [A]=[A]0/2.
- Derivation: Substituting values into the law yields k=t1/22.303log2⟹k=t1/20.693.
- Result: t1/2=k0.693.
- Conclusion: The half-life is independent of initial concentration. It is determined solely by the rate constant k (which is itself dependent on temperature).
This easy difficulty chemistry question is from the chapter chemical kinetics, covering the topic of first order half-life. It appeared in the 2025 exam.
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