Activity No. 6 Separation Techniques Used in Organic Chemistry: Fractional Distillation

fractional distillation

- Distillation can be used to separate volatile liquids by a process known as ___________.

Distillation

- is the oldest method used for separating mixtures of liquids. - exploits the fact that different liquids have different boiling points. When a mixture of liquids is heated, the liquid with the lower (or lowest) boiling point vaporizes first.

a positive azeotrope or minimum-boiling mixture, a negative azeotrope or maximum-boiling mixture

Every azeotrope has a characteristic boiling point, which may be lower (_____________________) or higher (____________________) than the boiling points of the individual liquids that make up the azeotrope

boiling points

If the process is repeated a sufficient number of times, a separation of the two volatile components can be achieved. Thus fractional distillation can separate two or more liquids making use of their differences in ___________.

Fractioning column

Name one piece of apparatus that is not used in a simple distillation but is used in a fractional distillation.

The outcome of the fractional distillation is concentrated alcohol. They are both flammable but the distillate or the ethanol vapor is flammable due to the higher concentration made by distillation.

Tests on the distillate and the original solution: Flammability. What are the expected results of this procedure? Explain your answer

The odor may be a pungent odor since the distillate contains a higher-concentrated fraction of ethanol. The ethanol contains 40% so it could be a lot stronger than the smell of the original solution. There is an odor of a strong alcoholic scent since the distillation made a high-grade ethanol.

Tests on the distillate and the original solution: Odor What is the expected odor of the first five fractions? Explain your answer

forerun.

The first distillate produced from such a mixture is called the __________

Boiling chips are small, insoluble, porous stones made of calcium carbonate or silicon carbide. Boiling chips provide nucleation sites so the liquid boils smoothly without becoming superheated or bumping it boils calmly. Always use a boiling chip when heating a solvent. Never add a boiling chip to a solvent which is already hot, because it can cause solvent to boil over violently.

What is a boiling chip? How does a boiling chip regulate boiling? When should a boiling chip be used?

78 oC

What is the approximate temperature of the first drop

The temperature of the first five fractions will be 78 degrees Celsius and not exceeding to 100 degrees. When the ethanol reaches its boiling point, the vapor will automatically passes to the condenser where it is cooled down and condensed. And after that, it will become liquid since it is converted in a liquid form. The temperature in the distilling flask will continuously rise when heated

What is the expected temperature range of the first five fractions? Explain your answer

The condenser converted gas to liquid. A liquid in flask at left is heated by the blue mantle to the boiling point. The vapor is then cooled as it goes through the inner tube at the condenser. There it becomes liquid again, and drips into the smaller collecting flask at right, immersed in a cooling bath.

What is the purpose of a condenser? How does a condenser operate?

The substance with the lower boiling point came off the column first because it is more volatile than the substance with the higher boiling point

Why did your lower boiling point substance "come off" the column prior to your higher boiling substance?

To monitor the temperature of the vapor and determine if the evaporation starts. If it is low or closely to its boiling and to read if the substance meets its boiling point.

Why should the bulb of the thermometer be placed below the side arm of the distilling flask?

azeotrope

also called a constant boiling mixture, is a mixture of two or more liquids at a specific ratio, whose composition cannot be altered by simple distillation.

fractional distillation

is used for the separation of a mixture of two or more miscible liquids for which the difference in boiling point is less than 25 kelvin