# The Concentration-Time Equation

The first-order rate constant for the decomposition of an insecticide in water at degC is 1.45 1/yr. A quantity of this insecticide is washed into a lake on June 1, leading to a concentration of 5.0 x 10-7 g/cm3 of water. Assume that the effective temperature of the lake is degC.

a. What is the concentration of the insecticide on June 1 of the following year?

b. How long will it take for the concentration of the insecticide to decrease to 3.0 x 10-7 g/cm3?

https://brainmass.com/chemistry/chemical-kinetics/the-concentration-time-equation-42552

#### Solution Preview

The first order rate equation is:

ln([A]t/[A]o) = -kt

where [A]t is the concentration at time t, [A]o is the ...

#### Solution Summary

The solution provides a clear, concise set of calculations to find the concentration of leaked insecticide in a lake using the concentration-time equation, accompanied by written explanation of the relevant theory where needed.