If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:
t = 0.693/k
t = 6.909/k
t = 4.606/k
t = 2.303/k
Option 3
For first order reaction,
Option 1)
t = 0.693/k
Option 2)
t = 6.909/k
Option 3)
t = 4.606/k
Option 4)
t = 2.303/k