أســــئــــلــتــــنــــــا في كـــــيمــــيــاء 202 نضــــعــهـــا هنــــــا ..

[البرق9]

عندي سؤالين

It takes 42min for cocntration of reaction in a first-order reaction to drop from 0.45Mto0.32M at25C. How long will it take for the reaction to be 90% complete >

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acertain first -order reaction a________b is 25% complete in 42min at 25c . What is the half-life of the reaction ?