Question

In the early stages of an action, the herbicide "Spartan Green" is planned to be applied to kill the vegetation onsite so the site can be cleared. If the equilibrium concentration of Spartan Green in the soil after a big rainfall event is 1,312.5 mg/kg soil, determine the equilibrium concentration of the chemical in the water that is in contact with the soil. The following reaction applies: SpartanGreen(aq)↔ SpartanGreen(ads s Kd =12,500 mg/kg soil per mg/L water

Answer 1

Answer:

Equilibrium Concentration = 0.105mg/kg

Explanation:

Let initial concentration be C₀

S(aq) at initial = C₀ , S(s) at initial = 0

S(aq) at equilibrium  = C₀ - Xe , S(s) at equilibrium = Xe

Xe = 1312.5 mg/kg

At equilibriuim Kd = [S(s)]/[S(aq)]

12500 = 1312.5/(C₀ - 1312.5)

C₀ = 1312.605 mg/kg

Equilibrium Concentration = 1312.605 - 1312.5 = 0.105mg/kg