Pre-Lab Chapter 15 Oxidation of an Aromatic Side Chain PDF

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pre lab report chapter 15 for organic chemistry 2 of Oxidation of an Aromatic Side Chain...

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Sierra 1 Diana Sierra U01 Pre-Lab Chapter 15: Oxidation of an Aromatic Side Chain: Identification of an Unknown Chlorotoluene Purpose The purpose of this experiment is to use alkylbenzenes to undergo the oxidation process which will convert into a carboxylic acid that will get attached to the aromatic ring. Introduction In this experiment, we will discover the identity of one of our three obscure chlorotoluene by changing it over to its comparing benzoic acid and by obtaining its boiling point to also decide the % yield of our item toward the finish of the trial. For this to have the option to occur we will utilize the reflux apparatus; the word reflux signifies "to return" which is what the cycle involves. The purpose of this cycle is to maintain a steady temperature that is close to the boiling point then, at that point a condenser will consolidate the boiling delivered through the bubbling of dissolvable and return it to the response vessel. The reflux denounces sercan either be water cooler or air cooler. When we utilize the reflux apparatus, we will filter the solution and use recrystallization along with vacuum filtration to dry and wash our item to discover the data want. Toward the finish of the analysis, we investigate the information gathered and we determined the and respect be 6.98% and base of the liquefying point range gathered of 150C-153C we recognize our example to be 3-chlorobenzoic corrosive. Table of Contents Name Water Potassium Permanganate

Manganese Dioxide

Hydrochloric Acid

Structure

Formula

Solubility

Density

Molecula r Mass 18.015 g

MP 100°C

H 2O

Soluble in methanol, ethanol & acetone

1.00 g/mol

KMnO4

Soluble in water, acetone & methanol

2.7 g/cm3

158.034 g

Dec

MnO2

Soluble in water and HNO3 and soluble in HCl.

5.0 g/cm3

86.937 g

535° C

HCl

Soluble in water and in ethanol

1.18 g/cm³

36.46 g

85.05° C

Sierra 2 Benzoic Acid

Sodium Hydroxide

C7H6O2

NaOH

Sodium Bisulfite

NaHSO3

2Chlorotoluene

C7H7Cl

3Chlorotoluene

C7H7Cl

4Chlorotoluene

C7H7Cl

2Chlorobenzoi c Acid

C7H5ClO2

Soluble in water and in ethanol

1.27 g/cm ³

122.12 g

122.4 °C

Very soluble in water. Freely soluble in ethanol. Soluble in water and in parts of alcohol.

2.1 g/cm³

39.997 g

323 °C

1.48 g/cm ³

104.06 g

Dec

Miscible with alcohol, acetone, ether, benzene, carb on tetrachloride, and n-heptane; slightly soluble in water. Slightly soluble in water.

1.083 g/mL

126.58 g

-35.6 °C

1.072 g/mL

slightly soluble in water and soluble in alcohol, benzene, chloroform, and ether.

1.07 g/mL

Slightly soluble in water, alcohol, and ether. Soluble in benzene, carbon sulfide, ether, and carbon tetrachloride.

1.4 g/cm3

126.58 g

-47.8 °C

7.5 °C 126.58 g

156.57 g/ mol

158 °C

Sierra 3 3Chlorobenzoi c Acid

C7H5ClO2

Slightly soluble in water, benzene, carbon sulfide, ether, carbon tetrachloride, and alcohol.

1.5 g/cm³

156.57 g/ mol

158 °C

4Chlorobenzoi c Acid

C7H5ClO2

Slightly soluble in water, ethyl ether and chloroform. Insoluble in benzene, carbon tetrachloride and very soluble in ethanol.

1.5 g/cm³

156.57 g/ mol

243 °C

Questions 1. what substance produces the brown/black spot on the filter paper in step 4? Manganese dioxide. 2. Assume that your product has a m.p. of 187-190°C. Even though this value does not match any of the isomers, you could still reasonably state which chlorotoluene you started with. Explain. A possible may be para chloro toluene. The melting point decreases if the impurities present due to colligative effects. Therefore, starting with para chloro toluene would be the best option. 3. In what form is the product (the chlorobenzoic acid) in the clear filtrate after the brown precipitate has been removed? After the addition of the hydrochloric acid? The product will turn into a solid. 4. What happens to the pH of the reaction mixture as the oxidation process proceeds? It will come it to decrease because the oxidation of the aromatic side chain leads to a carboxylic acid. 5. Explain the use of the filter paper in this experiment? Also explain what the #42 indicated about the paper's properties.

Sierra 4 Filter paper is used for critical gravimetric analysis with the finest particle retention, # 42 indicates that its measurement. 6. Why do you use an ice/water mixture in step 8 for an ice bath rather than pure ice? The ice bath allows for a controlled temperature at about 0 and lets the cold temperature circulate.

Procedures 1. Collect a sample of an unknown chlorotoluene and record the number of the unknown collected for future data. 2. Gather 50 mL of water, 3 g of potassium permanganate and 1 mL of the chlorotoluene in a round bottom flask of 250 mL. Then, add 3 pellets of sodium hydroxide into the flask and add some boiling chips. Apart a few drops of your unknown for later use. 3. Prepare a simple reflux apparatus and grab a heating mantle. 4. Place at a high temperature until the purple color seems to be gone or for an estimated time of one hour. Then, stop heating anymore and allow the mixture to cool down. Remove the condenser and test for the permanganate. 5. If the permanganate is still present after an hour, add some amounts of 30% sodium bisulfite solution until you see the purple color has disappeared. 6. Meanwhile the mixture is still hot, filter the mixture through the Whatman filter paper #42. Do not use the used filter cake in the solid waste container label for chemical disposal. 7. Add 5 mL of concentrated hydrochloric acid to the filtrate, with stirring. A white precipitate of the chlorobenzoic acid will begin to form. 8. Let the solution cool down for a few minutes. Then, use an ice bath to complete the recrystallization process. 9. Vacuum filter the product. Wash away any precipitate with cold water. Dry your product by pressing the solid between two pieces of filter paper. 10. Look at the m.p. of your chlorobenzoic acid to guide yourself and help you determine which unknown chlorotuene you had. Determine your yield and identification of your unknown to your instructor....