What does fractional distillation mean in chemistry?

Answer 1

Fractional distillation is a manufacturing process that separates the different components (i.e. fractions 1/2 in a chemical mixture according to their different boiling points. The liquid is raised to boiling and vapors pass through a tubular column where temperature is gradually lowered along its length. Components (fractions) with a higher boiling point condense on the column and return to the solution. Fractions with a lower boiling point pass through the column and are collected. Gasoline, kerosene and naphtha are fractions separated from crude oil using fractional distillation.

Here's more in simple,

the basic principle of fractional distillation is of using the different boiling points of elements(parts) in a compound(a mixture). A fractional distillation process is done in a cylinder which has different compartments having different temperature points. When the mixture is kept in the cylinder, the elements which have the same boiling point as in the compartment it is in, it vaporizes and moves out through a pipe. The mixture goes on vaporizing as the temperature increases and at last all the elements are removed in separated drums where they are condensed and brought back to their normal state.

Another way of putting it is:

Fractional distillation differs from distillation only in that it separates a mixture into a number of different parts, called fractions. A tall column is fitted above the mixture, with several condensers coming off at different heights. The column is hot at the bottom and cool at the top. Substances with high boiling points condense at the bottom and substances with low boiling points condense at the top. Like distillation, fractional distillation works because the different substances in the mixture have different boiling points.

The simplest way is:

Fractional distillation is a form of distillation which is used when more than two liquids with different boiling points are to be separated.

Answer 2

The first thing that happens is that the liquid in your mixture with the lowest boiling point will vaporize and then condense on the border of your column. The heat will rise and the droplets on the walls will evaporate again and again until they reach the area where they are collected. The first few samples are going to be highly concentrated with your first substance. However, as heat goes up, the second mixture will also vaporize and therefore for the last samples, they are going to be mixtures with lower concentration of the second mixture.

Ex: 1st sample: 95% 1st substance, 5% second

2nd sample: 85% 1st, 15% second.

...

last sample: 50-50

Answer 3

Fractional distillation is used to break down crude oil into many different substances. This is done because crude oil in itslef cannot be used for anything, where as the substances it breaks down into and essential for every day life and are very useful.

How it works:

1. Crude oil is heated causing it to evaporate

2. The vapour rises up the tower

3. The different fractions will then condense at different temperatures depending on their boiling points

*As you go down the fractionation tower, the hydrocarbon molecules will get LARGER

*The smaller the hydrocarbon molecule, the more useful it is as a fuel - because it burns more easily

As the size of a hydrocarbon molecule increases...

-Its boiling point increases (stronger intermolecular forces between molecules)

-It becomes less volatile (does not evaporate as easily)

-It becomes less flammable (the hydrocarbon burns less easily)

-It becomes more viscous (thicker and does not flow as easily)

Once crude oil is separated by fractional distillation, cracking takes place.

See 'what is cracking?' for information on cracking...

Answer 4

Hydrocarbons (ie crude oil) comprises a mixture of hydrocarbon compounds. These compounds all have slightly different boiling and condensing points. Thus it is possible to heat up the crude oil and separate the individual components by collecting them at different points up a cooling tower through which the vapors are passed (a still). This process is called fractional distillation

Answer 5

Fractional distillation method is for separating the mixture in the petroleum of different hydrocarbons from one another before they can be useful to us.

Answer 6

Fractional distillation is a process used to separate components of a chemical mixture. This is usually performed by heating the compound and determining the boiling points of each component.

Answer 7

Fractional distillation is a method for the separation of liquids based on the differences between boiling points.

Answer 8

Fractional distillation is a method of separation based upon differences between boiling points of components.

Answer 9

A fractional distillator is an installation used to separate components of a liquid based on differences between boiling points.

Answer 10

Fractional distillation is used when separating miscible liquids example given water and ethanol