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Equal moles of A and B are mixed and the reaction is zero order in both A and B. After 1 hour, 75% of A has reacted. How long (in hours) until only 10% of A remains unreacted?

Correct answer: 1.2

Solution

Zero-order means fraction reacted is linear in time, so time scales as 90/75 of 1 hour = 1.2 h.

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