Suppose 100 moles of a chemical is spilled into a lake. After 15.0 days, the total amount of the chemical in the lake 3.50 moles. Assuming that the reaction followed first order kinetics and no chemical was lost due to advection or volatilization, then what is the rate constant for the degradation reaction? The units are 1/days.

Answer 1

100/2^n = 3.50
Solve for n = number of half lives.

half life = 15.0 days/n = ?

k = 0.693/t_1/2