# A first order reaction takes 23.1 minutes for 50% completion. Calculate the time required for 75% completion of this reaction. - Chemistry

A first order reaction takes 23.1 minutes for 50% completion. Calculate the time required for 75% completion of this reaction.

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

#### Solution

Let us first calculate k.

t1/2 = 23.1min

t1/2 =0.693/k

k = 0.693/23.1

k = 0.03

Now let us calculate the time required to complete 75% reaction.

k=2.303/tlog"" ([R_0])/([R])

0.03=2.303/tlog""100/25

0.03=2.303/tlog4

t=2.303/0.03 log4

t = 46.22mins

Concept: Integrated Rate Equations - Half-life of a Reaction
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