6) E

A – calcium carbonate is the solute whilst water is the solvent. Water can evaporate, leaving the solute behind in the container.

B – pentane and octane have different number of carbon atoms, and hence different chain lengths. Octane has 8 carbon atoms whilst pentane has 5. Therefore, boiling point of octane would be higher than pentane. Hence, pentane would evaporate first and then condense and separated from octane.

C – Silicon dioxide is not a good soluble solid and can easily be separated by filtration.

D – Sodium chloride and water have different boiling temperatures.

E – ethanol can dissolve in water and hence ethanol is not immiscible. Only immiscible substances can be separated by a separating funnel.