Organic chemistry question help?

Fractional distillation is the process to separate the components from a mixture of liquids by the difference in boiling points. The liquid mixture is heat to evaporate. The vapors of different components condense in the fractionating column and then evaporate again. The component with the lowest boiling point reaches the top of the fractionating column first, and condenses into liquid and is then collected. Consequently, the components are collected, and the last portion is the component with the highest boiling point.

It takes a long time to distil because it needs time to heat up the fractionating column by the hot vapors. The vapors of different components undergo repeated process of condensation and evaporation in the fractionating column, and a component goes into the condenser from the top of the fractionating column when the temperature of the top of the column is equal to the boiling point of this component.

The set-up of common distillation does not include a fractionating column, and thus its effect in separating liquid components is much lower than fractional distillation. Common distillation can be used to separate the liquid component from a mixture of a solid and a liquid, e.g. to separate water from salt solution, or separate liquid components from a mixture in which the difference between their boiling points is above 25°C.

Fractional distillation is important in chemistry. Apart from separating liquid components of mixture as described above, fractional distillation can be used to separate the liquid product from a reaction mixture.

Why so slow? You're processing vapors -- many liters -- to collect a few grams of products.
What's the point? Fractional distillation is equivalent to scores of repeated simple distillations.
Why important? Very convenient way to separate mixtures.
Fractions? First: 2-butanone, second: a mixture, last: 2-pentanone.