A first-order reaction has a rate constant of 0.00693 per min. What is its half-life? (ln 2 = 0.693)
Answer and explanation
Correct answer: D. 100 min
- Step 1: For first order t½ = 0.693/k. Step 2. t½ = 0.693 ÷ 0.00693 = 100 min. Answer: 100 min. Why not the others: 0.01 min is what you get if you invert the formula. 144.3 min is what you get if you use 1/k. 200 min is what you get if you double the half-life.
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