Question:
The rate constant for a first-order reaction is \(0.0693\ \text{min}^{-1}\). The time required for 75% completion of the reaction is:
The rate constant for a first-order reaction is \(0.0693\ \text{min}^{-1}\). The time required for 75% completion of the reaction is:
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For first-order reactions, use logarithmic decay formula.
Updated On: Jan 6, 2026
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The Correct Option is B
Solution and Explanation
75% completion means 25% remains:
\[
t=\frac{2.303}{k}\log\frac{1}{0.25}
=\frac{1.386}{0.0693}\approx20\ \text{min}
\]
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