The basic properties of phenol

Laboratory work №6. The basic properties of phenol

Experience 1. The formation and decomposition of phenolate

Reagents: phenol, 2 n Solution of sodium hydroxide, 2 n Solution of sodium carbonate, 2 n Solution sulfuric acid, 2n. The sodium bicarbonate solution.

a) To 0.1-0.3 g of phenol is added 1-2 ml of sodium hydroxide solution. Gradually the dissolution of the phenol. The mixture was heated until a homogeneous liquid. The cooled solution was poured dilute sulphuric acid. Observed turbidity.

Write a balanced equation for the formation of sodium phenolate. Explain the cause of turbidity of the mixture during the interaction with sulfuric acid.

b) For the experiment in two test tubes is placed 0.1-0.3 g of phenol. One pour 1-2 ml of the carbonate solution in the other the same volume of sodium bicarbonate. Is there dissolution of the phenol and formation of a homogeneous liquid in both pribisko? As evidenced by this experience? Write a balanced equation for the reaction of sodium carbonate with phenol. What properties manifests phenol in the interaction with sellasamy and sodium carbonate?

Experience 2. Bromation of phenol

Reagents: phenol, bromine water

Equipment: pipettes.

The tube was placed 1 ml of an aqueous solution of phenol and shaking added dropwise bromine water.The solution becomes colorless and a white precipitate vypadaet. When you add ibyte bromine water, the precipitate turns to yellow.

Write a balanced equation for the reaction of bromination of phenol and consider the mechanism of this process. Compare the ease of bromination of phenol with benzene and toluene. What is the product formed by the action of excess of bromine water to the tribromophenol?

Experience 3. Obtaining and properties of picric acid

Reagents: Phenol, сoncentrated sulfuric acid, nitric acid, glucose, sodium carbonate.

a) In the test tube gently mixed 5.5 g of the phenol with 1.5 ml of concentrated sulfuric acid, then the mixture was heated until a homogeneous liquid. The cooled liquid is carefully poured into a test tube containing 2 ml of water, and gradually added to fuming nitric acid. The solution becomes dark red color, and then the mixture was heated 15 min in a water bath and after cooling, diluted with an equal volume of water. Highlighted in yellow crystals of picric acid.

b) In a test tube put a few crystals of picric acid, 3 ml of a solution of sodium carbonate and 1.0 g of glucose. The mixture was heated and boiled for a few minutes. Color changes to red, and the acidification becomes orange-yellow.

b) To a saturated solution of picric acid add a few drops of sodium hydroxide solution until alkaline reaction on litmus. The light yellow color becomes dark orange. What is the cause of discoloration?

d) Dyeing with picric acid. In a saturated aqueous solution of picric acid, immerse the wool or silk and heated in a boiling water bath for 15-20 min. Then decanted, the material was washed several times in water, drained and dried. The material is dyed in bright yellow. Picric acid interacts with the amino groups of proteins, giving an insoluble yellow food. Is it possible to dye picric acid paper? Give a reasoned answer.

Experience 4. Sulfonation of phenol

Reagents: phenol,concentrated sulfuric acid.

To 3 ml of concentrated sulphuric acid gradually added with shaking 2 g of phenol, the mixture is poured into two test tubes, one of them gradually add 3-5 ml of cold water. The phenol is excreted in the form of turbidity, there is the smell. Another tube with homogeneous mixture is heated on a water bath for 5 min and polioksidony it is poured in 10 ml of cold water. The resulting mixture remains uniform, the smell of phenol is missing.

Explain the origin of changes in the mixture. Write a balanced equation for the sulfonation of phenol. What type of this reaction?

Experience 5 . The oxidation of phenol

Reagents: phenol, 1 per cent potassium permanganate solution, 5 percent solution of sodium carbonate.

Equipment: pipettes.

In a test tube, dissolve 0.1 g of phenol in a solution of sodium carbonate. Then under agitation dropwise added a solution of potassium permanganate. The solution becomes colourless, the brown precipitate falls.

Explain the observed change of color.

Лабораторная работа №6.  Основные свойства фенола

Опыт 1. Образование и разложение фенолятов.

Реактивы: фенол, 2 н. Раствор гидрокида натрия, 2 н. Раствор карбоната натрия, 2 н. Раствор серной кислоты, 2н. Раствор гидрокарбоната натрия.

а) К 0,1-0,3 г фенола прибавляют 1-2 мл раствора гидроксида натрия. Постепенно происходит растворение фенола. Смесь нагревают до получения однородной жидкости. К охлажденному раствору приливают разбавленную серную кислоту. Наблюдается помутнение раствора.

Напишите уравнение образование фенолята натрия. Обьясните причину помутнение смеси при взаимодействии с серной кислотой.

б) Для проведения опыта в две пробирки помещают по 0,1-0,3 г фенола. В одну приливают 1-2 мл раствора карбоната, а  в другую-такой же обьем гидрокарбоната натрия. Наблюдается ли растворение фенола и образование однородной жидкости в обеих прибирках? О чем свидетельствует этот опыт? Напишите уравнение реакции карбоната натрия с фенолом. Какие свойства проявляет фенол при взаимодействии со щеллочами и карбонатом натрия?

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