Experiments related to phenol, what are the relevant experiments to verify the acidity of phenol?

1.Take 2ml of phenol solution in the test tube, add litmus reagent dropwise, and observe the phenomenon.

2.Take a small amount of phenol solids in the three test tubes, and add 2-3 ml of sodium hydroxide solution, 2-3 ml of sodium carbonate solution, and 2-3 ml of sodium bicarbonate solution to them respectively, shake fully, observe and compare the phenomenon (pay attention to whether there are bubbles in the test tube with salt solution. ）

3.Take 2ml of sodium hydroxide solution in the test tube, add 2-3 drops of phenolphthalein test solution, and then add a small amount of phenol solids to observe the color change. 1.Phenol cannot make litmus red.

2.Phenol solids are easily soluble in sodium hydroxide solution and sodium carbonate solution, and no bubbles are generated; Insoluble in sodium bicarbonate solution.

3.Phenol makes the red solution (sodium hydroxide solution dropped, with phenolphthalein solution) gradually lighter. In the phenol solution just prepared, the sodium hydroxide solution is added drop by drop while shaking until it is just clear, and the product is sodium phenol.

Then carbon dioxide gas is continuously introduced, and the solution becomes turbid again (carbon dioxide and water form carbonic acid, and carbonic acid reacts with sodium phenol to form phenol and sodium bicarbonate).

To sum up, according to the principle of strong acid to weak acid, the acidity can be known: H2CO3 > NaHCO3. It is also known that carbonic acid is more acidic than phenol.

1) Drip bromine water can fade the bromine water 2) With litmus reagent, litmus turns red when exposed to acid and blue when exposed to alkali 3) Trivalent iron ions can be tested. This should be on the 4) of the book wheel no tan on the 4) can be with sodium hydroxide.

React. In the cloudiness of benzophenol.

The sodium hydroxide ridge radicalization solution was added drop by drop to the solution, and it became clear, indicating that it could react with sodium hydroxide. Phenol is acidic.

5) React with sodium hydroxide to generate sodium phenol and sodium bicarbonate.

6) Use ferric chloride to test, the solution will be purple.

7) Add sodium bicarbonate to generate carbonic acid, which is weaker acidic than phenol, so it can be proven.

8) Add to NaOH phenolphthalein mixture.

Excessive addition can fade.

Experiment 1Add phenol and 5ml of water to a test tube. Shake to dissolve, and add 1 drop of litmus solution to the tube, which is reddish (pH 5). This experiment proves that phenol has a weak acidity that makes litmus reddish. Experiment 2Add 5 to a tube

ml of water and l drop of litmus solution, mixed well, add 1 drop of phenol solution, the color has no obvious change (at this time, the phenol is diluted, and the pH value of the solution does not change much). This experiment demonstrates that phenol is a wide-cavity acidic to the extent that it is not sufficient to discolor litmus when it is diluted in solution.

Actual acceptance for inspection 3

CO is introduced into the above tubes. After that, the color quickly turned red, proving that phenol is a weaker acid than carbonic acid.

There are six preparation methods of phenol: sulfonation, cumene, chlorobenzene hydrolysis, crude phenol refining, benzene oxidation and toluene oxidation. China mainly uses sulfonation and cumene methods.

The sulfonation method uses benzene as raw material, sulfonates with sulfuric acid to generate benzene sulfonic acid, neutralizes it with sulfurous acid, and then uses caustic soda for alkali melting, and is prepared by sulfonation and vacuum distillation and other steps.

The cumene method is that propylene and benzene are formed under the action of aluminum trichloride catalyst, and cumene is oxidized to produce cumene peroxide, which is then decomposed with sulfuric acid or resin. Phenol and acetone are obtained at the same time. Each ton of phenol is about co-produced acetone.

1. Nitrification of phenol.

C h o +co +h o = c h oh + HCO 2, the reaction of phenol and formaldehyde is essentially a polycondensation reaction, which is used to make phenolic resin in production.

C h oh + hcho c h ohch + h o3, phenol reacts with bromine to form tribromophenol.

3br +c h oh c h oh ) br +3hbr4, phenol reacts with sodium hydroxide to produce sodium phenol and water.

C h oh + Naoh C h ONA+ H o Physical properties of phenol: phenol is slightly soluble in water at room temperature, soluble in benzene and alkaline solution, soluble in ethanol, ether, chloroform, glycerol and other organic solvents, insoluble in petroleum ether.

Bromine water or FeCl3 solution can be used for testing.

with bromine water. Phenomenon: Bromine water added to phenol will produce a white precipitate.

Principle: Bromine and phenol produce white tribromophenol C6H6OH + 3 BR2 = C6H3OHbr3 3HBR

Note: The phenol concentration should not be too large, otherwise the generated C6H3OHBR3 will be dissolved, and no precipitate will be produced.

with FeCl3 solution.

Phenomenon: Phenol adding FeCl3 solution to phenol will turn the solution purple Principle: phenol and FeCl3 generate purple [Fe(C6H5O)6]3-complex ion FeCl3 + 6 C6H5OH === H3[Fe(C6H5O)6] +3 HCl

Note: This phenomenon is obvious, note that the solution turns purple, not produces purple precipitate.

for copper hydroxide.

Heat the water bath.

Ferric chloride.

a is ethanol. b is phenol.

c is acetic acid. d is acetaldehyde.

Explanation: After reading the question first, the solution of test tube B turned purple, and the other 3 test tubes did not change, and it was inferred that only phenol met ferric chloride to produce purple. From (1) and (2), it can be seen that the reagent is a copper salt, and then copper hydroxide only reacts with acetic acid to form a copper acetate solution, and is heated with acetaldehyde water bath to produce a brick-red precipitate, and the precipitate is cuprous oxide, and c is acetic acid d is acetaldehyde reagent is copper hydroxide, and the operation is (water bath heating).

There are many methods for the detection of phenol concentration, including GC and HPLC, as well as ultraviolet-visible spectrophotometry and 4-aminoantipyrine spectrophotometry (GB T 7490-1987). It is relatively simple to use UV-vis, but it is necessary to make a standard working curve of phenol, and the detection wavelength is about 270nm.

FeCl3 solution (purple reaction) and bromine water (white precipitate) can be used

Pre-sulfonated benzene: C6H6 + H2SO4 (concentrated, heated) --C6H5-SO3H

C6H5-SO3H+NaOH(L)-C6H5-OH was prepared by adding NaOH and eutectic reaction with it

Carbon dioxide is introduced into sodium phenol, and because it's a reversible reaction, there's an excess of carbon dioxide.

To make phenol, you can first use liquid bromine, not bromine water, and the catalyst can use Fe is actually Febr3 to replace the benzene mold slag to generate bromobenzene and then hydrolyze to produce phenol.

The halogenated compounds of benzene are difficult to be carefully dissolved in water and require high temperature and high pressure, so benzene and concentrated sulfuric acid are generally sulfonated first, benzene + concentrated sulfuric acid - benzene sulfonic acid, that is, a hydrogen atom is replaced by a sulfonic acid group (SO3H), and then reacts with NaOH to prepare phenol.

Phenol can be used to disinfect surgical instruments and the treatment of excrement, **sterilization, itching and otitis media. A small fraction of phenol is exposed to air and is oxidized by oxygen to quinone and has a pink color. When ferric ions turn purple, this method is usually used to test phenol.