Particles are not separated from a solution according to their shape.

At a refinery, petroleum is separated into several components by a process called fractional distillation using a fractionating column. Which of the following statement is incorrect about the process?
(I) Temperature decreases from the bottom to the top of the column
(II) At each level in the column only one compound is collected
(III) The fraction collecting at the top of the column is less volatile
(IV) The fraction with the highest boiling point condenses first and gets collected near the base of the fractionating column.

Discuss the role of centrifugation in removing the precipitate formed in a solution.

Name the process associated with the following:
Milk is churned to separate cream from it.