A first-order reaction has a hall-life of 21.3s. How long does it take for the concentration of the reactant in the reaction to fall to one-eighth of its initial value?
It would take approximately
Each equation I used is assuming this reaction's kinetics are of the first order, which is cited. The first equation is a simplified version for the half life of a first order reactant, and the second equation is the general equation for first order reactions in chemical kinetics.