Are nitrobenzene and benzene miscible with each other? What is the difference between fractionation

Can nitrobenzene and benzene be separated with a separating funnel.

Answer: It is not possible to separate similar miscibles but the boiling point is different and fractional distillation can be used.

Fractionation and distillation are mainly what is the difference between the device and the process.

Answer: Fractionation: It is distilled multiple times; It is the process of heating a mixture, cooling and separating into a relatively pure single substance according to the different boiling points of each component in the mixture------ such as the fractionation of coal tar; Fractionation of petroleum

Distillation is a combination of two processes: heating a liquid substance to boiling and turning it into vapor, and cooling the vapor into a liquid. This operation can be used to separate, remove impurities, and purify substances; Fractionation, like distillation, is also the operation of separating or purifying substances by using the different boiling points of each substance in the mixture, strictly controlling the temperature.

They are all organic solvents and are miscible, so you can't use a separating funnel. Fractionation and distillation are both physical changes that use the different boiling points of substances to separate them, the only difference is that fractionation generally refers to the separation of several substances at the same time, while distillation only separates two substances.

They are all organic solvents and should be miscible with each other, and cannot be separated with a funnel.

It cannot be separated from similar miscible but with different boiling points and can be fractionated by fractionation.

Distillation: The liquid is heated to the boiling point, the liquid begins to boil and gradually turns into vapor, so that the vapor is cooled by the condensing device, and the liquid is obtained again by condensation. Distillation has the following uses:

Separation of liquid mixtures (separation can only be done effectively if there is a large difference between the boiling points of the mixture components); determination of the boiling point of compounds; Extraction of liquids or solids with low melting points to remove non-volatile impurities; Solvents, or concentrated solutions.

Fractionation: Although distillation is a common method for separating liquid organic matter, its separation efficiency is not high. Sufficient separation can only be achieved if the boiling points of the separated components differ by more than 150 degrees Celsius.

For mixtures with similar boiling points, it is not possible to separate the components in an ordinary distillation, and they can only be gradually separated after multiple distillations in stages. Doing so is cumbersome and wasteful. Therefore, the method of fractional distillation is adopted.

Fractionation is actually the result of boiling vaporized mixtures passing through a fractionation column and heat exchange in the column. The substances with high boiling point in the rising vapor are first condensed back into the distillation flask, and the vapor with low boiling point continues to rise, so that the vapor is cooled by the condensing device, and the liquid is obtained again by condensation, so that the substances with different boiling points are separated.

To put it simply, in order to achieve full separation in distillation, the boiling point difference is required, and fractionation can obtain better separation results than distillation (especially mixtures with similar boiling points, such as petroleum); The biggest difference in the device is that the distillation unit round bottom flask is connected to the distillation head, while the split device round bottom flask is connected to the fractionation column.

Extraction methods can be used to separate nitrobenzene and benzene, but it is necessary to select a suitable solvent, and to take into account the physicochemical properties and chemical reaction characteristics of the two substances, as well as other experimental slag wheel conditions. The following are brief steps for the extraction of nitrobenzene and benzene:

1.Choose the right extraction solvent: Choose an extractant that is selective for nitrobenzene, such as dimethylbenzene or benzyl alcohol.

2.Mixture preparation: Nitrobenzene and benzene are mixed in a certain proportion to obtain a mixture.

3.Extraction: The mixture and extraction solvent are added to the separating funnel, shaken and stirred so that the two substances are distributed differently in the two-phase solution.

4.Separation: After the separation of the two-phase sodium solution, the upper and lower liquids are collected respectively, and the separation products of nitrobenzene and benzene can be obtained.

It should be noted that the extraction operation needs to take into account multiple factors such as temperature, pressure, relative solubility, etc., to ensure the accuracy and reliability of the experiment. In addition, in the actual operation process, it is also necessary to pay attention to the problems of solvent selection and operation safety.

Physical Method: Distillation.

Chemical method: add an excessive amount of potassium permanganate (KMNO4) acidic solution to the mixed liquid, oxidize ethylbenzene (C6H5CH2CH3) to phenylacetic acid (C6H5CH2CH2COOH), phenylacetic acid is soluble in water, add water to the mixture, and then pour it into the separating funnel**, stand and stratify, and pour out the upper layer of benzene (C6H6).Excess calcium hydroxide solution was added to the lower liquid tartar body to generate calcium phenylacetate [Ca(C6H5CH2CH2COO)2] precipitate, filtered, and the precipitate was removed.

Excessive dilute hydrochloric acid (HCl) is added to the precipitate, and then excess ascorbic acid solution (C6H8O6, vitamin C) is added, **, ascorbic acid reduces the generated phenylacetic acid to produce ethylbenzene and floats on the liquid surface, and divides the denier liquid to obtain ethylbenzene.

Laboratory conditions allow distillation, and the isomers of xylene, p-, and o-xylene are less than 10 degrees apart before they are purified by this method. Since the molecular weight of halobenzene is larger than the former, other methods can also be used to try mass extraction.

Distillation. Benzene and nitrobenzene can be separated by distillation。Distillation is the process of separating substances by using the different boiling points of each component in a mixed liquid or liquid-solid system.

The advantage of this operation is that it does not introduce new impurities. Nitro front This benzene and benzene are miscible but have different boiling points and can be separated by distillation of silver fiber.

Benzene and bromobenzene are miscible with each other, the solution is not stratified, and the method of distillation is used to separate, and the method of separating the liquid cannot be used, so it is wrong;

The solubility of potassium nitrate and sodium chloride varies with temperature, and can be separated by crystallization, so it is correct.

Water and nitrobenzene are immiscible with each other and can be separated by separating liquids, so they are correct;

Ethanol (boiling point is similar to the boiling point of ethyl acetate (boiling point is similar, can not be separated by distillation, hand years can be added saturated sodium carbonate solution separation, so it is wrong

So choose A