Question

In this experiment, 1-2 mL of saturated sodium chloride is used to transfer the crude product after the initial distillation. Why is saturated sodium chloride, rather than pure water, used for this procedure?

Answer 1

Because it helps to remove water from the system.

Step-by-step explanation:

The saturated sodium chloride solution has a strong affinity for water molecules and there is the possibility of changing the saturated solution to a dilute solution in the presence of pure water. Because of these reasons, the saturated sodium chloride solution removes water molecules from the system to become a diluted solution. That is the reason why the saturated solution was used instead of pure water.

Answer 2

Saturated sodium chloride is used to transfer the product rather than water since it is not polar and rinsing the product with water would revert any 4-methylcyclohexene back to 4-methylcyclohexanol in the Hickman Head and thus lowering the percent yield; using water would shift the equilibrium towards the reactants. Also sodium chloride removes the small amount of phosphoric acid and also a small amount of water. If one were to add water, both 4-methylcyclohexene and phosphoric acid are partially soluble making difficult to remove the water later; sodium chloride makes the water less reactive so easier to remove by making the aqueous later more polar.