Question

A student was performing an extraction procedure of o-Xylene from water into octanol. The total mass of o-Xylene was 0.10 gram (molecular weight 106.2 g/mole). The volume of water was 990mL and volume of octanol 10 mL. There is a head space of 200 mL above the solution and it is sealed. Temperature was 25°C. The Henry’s Law constant for o-Xylene is 0.2Matm-1 and logKOW is 3.12. Calculate the concentrations of o-Xylene in the air above the solution in μg/m3, concentration in water and octanol in mg/L.

Answer 1

We start with 0.1 g 0-xylene in the H2O. After extraction let x = grams in octanol, then 1-x = grams in water.
1318 = [(x/10)]/[(1-x)/990]
Solve for x and 1-x. This only gives you the amount in octanol and amount in H2O in grams. Convert to mg/L.