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Question
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)
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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
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