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For the reaction P + Q -> R + S, the time required for 75% of P to react is twice the time required for 50% of P to react. The plot of [Q] versus time is linear (decreasing). What is the overall order of the reaction?
- 2
- 3
- 0
- 1
Correct answer: 1
Solution
For first order in P, t(75%) = 2 * t(50%) since each half-life is constant (50% takes one half-life, 75% takes two). [Q] decreasing linearly means zero order in Q, so the overall order = 1 + 0 = 1.
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