Question

1. If three jars of the same amount of hexachlorobenzene, ethanol, and benzyl alcohol are left open in a room, which of them would have the highest air concentration after the same period? Why? You can ignore degradation process in this question. Hint: a higher vapor pressure would mean the chemical has a higher tendency to evaporate.

2. Which of these chemicals are considered persistent organic pollutants by the Stockholm Convention (Links to an external site.)Links to an external site.? Name at least 3 physicochemical properties you think make this chemical persistent

Answer 1

Hexachlorobenzene will have highest air concentration. Because, in liquid statr hexachlorobenzene molecules remain associated by weak van der Waals forces of attraction. Hrnce they can easily go into the vapor phase.

On the other hand, the remaining two substances (EtOH and benzyle alcohol) form H-bond in solution which are relatively stronger than van dar Waals force. Due to such strong attraction they cannot leave the liquid surface with ease.