JEE Main 2026 Apr 5 Shift 1, Chemistry Q25: Reactions of Various Orders

JEE Main2026Apr 5, Shift 1Chemistry

If the half life of a first order reaction is 6.93 minutes then the time required for completion of 99% of the reaction will be _______ minutes.

(Given : $lo g 2 = 0.3010$ )

Your answer

Solution

For a first-order reaction, $k = \frac{ln 2}{t _{1/2}} = \frac{0.693}{6.93} = 0.1 min^{- 1}$ .

Time for 99% completion: $t = \frac{1}{k} ln \frac{[ A ] _{0}}{[ A ] _{t}} = \frac{1}{0.1} ln \frac{100}{1} = \frac{2 ln 10}{0.1} = \frac{2 \times 2.303}{0.1} \approx 46.06$ min.

Rounded: $46$ minutes.

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JEE Main 2026 Apr 5 Shift 1, Chemistry Q25: Reactions of Various Orders

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