Problem 3
Qualitatively predict the relative extent of downward movement of the
herbicides aldicarb and trifluralin if they are applied to soil containing
\(3.6 \% \mathrm{OM}\) just before a rain storm which causes the water to
penetrate \(5 \mathrm{~cm}\) into the soil.
Problem 5
The \(t_{1 / 2}\) for the hydrolytic degradation of the carbamate insecticide carbaryl is reported to be 31 days at \(6^{\circ} \mathrm{C}\) and 11 days at \(22^{\circ} \mathrm{C}\). Calculate the activation energy for the reaction. Write an equation for the hydrolysis of this pesticide.
Problem 6
At \(22^{\circ} \mathrm{C}\), the organophosphorus compound diazinon has a degradation \(t_{1 / 2}\) of 80 days in river water, and 52 days in the same water after filtration. In contrast, the triazine cyprazine has corresponding \(t_{1 / 2}\) values of 190 days and 254 days. Suggest reasons why filtration increases the \(t_{1 / 2}\) in one case and decreases it in the other.
