Q13 of 26 Page 1

Show that the time required for the completion of 3/4th of the first order reaction is twice the time required for the completion of half of the reaction.

Given, order of reaction = 1


For completion of 3/4th reaction, [R] = [R0] - [R0] = [R0]


For 1st order reaction, K =


t =


t = = …1


Now, for a 1st order reaction, K =


= …2


From equation 1 and 2, t = t1/2


I.e. time required (t) for the completion of 3/4th of the first order reaction is twice the time required for the completion of half of the reaction (t1/2).


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