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For the thermal decomposition of a gas, the half-life period varies with the initial partial pressure as below. Determine the order of the reaction. P (mmHg): 500 250 t1/2 (min): 235 950 [Given log(23.5) = 1.37; log(95) = 1.97; log 2 = 0.30]
- 1
- 2
- 2.5
- 3
Correct answer: 3
Solution
t1/2 is proportional to 1/P^(n-1); plugging the two data points gives (n-1) = 2, so n = 3.
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