Advertisements
Advertisements
Question
What is the difference between distillation, distillation under reduced pressure and steam distillation ?
Advertisements
Solution
The differences among distillation, distillation under reduced pressure, and steam distillation are given in the following table.
| Distillation | Distillation under reduced pressure |
Steam distillation |
| It is used for the purification of compounds that are associated with non-volatile impurities or those liquids, which do not decompose on boiling. In other words, distillation is used to separate volatile liquids from non-volatile impurities or a mixture of those liquids that have sufficient difference in boiling points. | This method is used to purify a liquid that tends to decompose on boiling. Under the conditions of reduced pressure, the liquid will boil at a low temperature than its boiling point and will, therefore, not decompose. | It is used to purify an organic compound, which is steam volatile and immiscible in water. On passing steam, the compound gets heated up and the steam gets condensed to water. After some time, the mixture of water and liquid starts to boil and passes through the condenser. This condensed mixture of water and liquid is then separated by using a separating funnel. |
| Mixture of petrol and kerosene is separated by this method. | Glycerol is purified by this method. It boils with decomposition at a temperature of 593 K. At a reduced pressure, it boils at 453 K without decomposition. | A mixture of water and aniline is separated by steam distillation. |
RELATED QUESTIONS
How will you separate a mixture containing kerosene and petrol (difference in their boiling points is more than 25°C), which are miscible with each other?
On what principle are the following methods of separation based? Give one example of a mixture for each of the methods mentioned in which they are used
Fractional distillation :
Select the correct alternative from the choices given for the following statement:
Components of crude petroleum can be separated by
Write an answer to the following question in your own words.
Where are the methods of separation by distillation and by separating funnel used? Why?
Pure water from impure water
- Give the principle involved in the separation of the mixture
- Give the technique of separation of the mixture.
Choose the correct option.
Which of the following methods can be used to separate two compounds with different solubilities in the same solvent?
Why is a condenser used in distillation process?
What is the difference between simple distillation and fractional distillation?
Alcohol can be separated from water by ______.
Which of the tubes in Fig. 2.1 (a) and (b) will be more effective as a condenser in the distillation apparatus?
Two liquids (A) and (B) can be separated by the method of fractional distillation. The boiling point of liquid (A) is less than boiling point of liquid (B). Which of the liquids do you expect to come out first in the distillate? Explain.
Draw a diagram of bubble plate type fractionating column. When do we require such type of a column for separating two liquids. Explain the principle involved in the separation of components of a mixture of liquids by using fractionating column. What industrial applications does this process have?
Explain the factors, which will affect the rate of evaporation, taking examples from our daily life experiences.
What is distillation?
