Organic Chemistry Laboratory – CH 200L (2012 – 2013) 2B-Ph Group 9 Experiment 10
Identifying Carboxylic Acids and Derivatives Through Classification Tests
Bianca Therese Rivera, Camille Aliana Rivera, Zarah Mae Roxas,
Ma. Rosario Teresa Saylo, Jean Darlene Semilla and Adrian Yu
Department of Pharmacy, Faculty of Pharmacy
University of Santo Tomas, Espana Street, Manila 1008
Date Submitted: September 13, 2012
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Abstract
Carboxylic acid derivatives namely, acyl halides, acid anhydrides, esters and amides were classified through different reactivity tests. The samples used were acetyl chloride for acyl halide group, acetic anhydride for acid anhydride group, ethyl acetate for ester group,
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Methodology
A. Hydrolysis of Acid Derivatives
A.1. Acyl Halides and Acetic Anhydrides
One mL of water was placed in each two test tubes. The samples, acetyl chloride and acetic anhydride, were added separately to the test tubes by placing ten drops of each sample. A warming effect was noted from the reaction. The resulting mixtures were divided into two portions. To the first portion, an amount of one mL of 2% silver nitrate (AgNO3) was added. The formation of precipitate was observed. To the second portion, one mL of saturated sodium bicarbonate (NaHCO3) and the evolution of gas was noted.
A. 2. Esters
To one mL of the sample, ethyl acetate, two mL of 25% sodium hydroxide (NaOH) was added. The mouth of the test tube was covered with a marble and was heated in a boiling water bath for five minutes. The mixture was neutralized with 10% HCl solution. The odor was observed with a wafting motion.
A. 3. Amides
One mL of benzamide was treated with five mL of 10% sodium hydroxide (NaOH) and was heated to boiling afterwards. The reaction of the gas evolved during heating was tested by placing a piece of moist red litmus paper over the test tube. The observed reaction was noted.
B. Alcoholysis: Schotten-Baumann Reaction
A mixture of ten drops of acetic acid, one mL of ethanol and five drops of concentrated sulfuric acid
Atoms are the basic units of matter and all life is based on them. Life on earth is based on the element carbon. It is a highly versatile atom able to form four covalent bonds with itself or other atoms such as hydrogen and water. Atoms combine to form molecules and those that are carbon based are referred to as organic molecules. Organic molecules occur in four different types in living cells; carbohydrates, lipids, proteins and nucleic acids. They are also known as hydrocarbons due to the presence of both hydrogen and carbon. Carbohydrates are made up of carbon, hydrogen and oxygen in the ratio 1:2:1. They are important sources of energy and are classified in three main groups; monosaccharides, disaccharides and polysaccharides.
The main objective of this experiment is to differentiate between a physical change and a chemical change.
In this part of experiment, alcohol(2ml) and CH3COOH(1ml) will react to produce an ester, the ester's odor can then be compared with that of the ester bank to determine the identity of the ester. This is done by mixing the reagents in the solution with a glass stirring rod and then to further dissolve the solution, it
In this experiment, you have been asked by your teacher, to investigate the design of a small-scale airbag system they want to produce as a child safety device to put into baby strollers. Because of sodium azide’s toxicity (which is used in many vehicular airbags), it is suggested you use the reaction of NaHCO₃ (sodium bicarbonate or baking soda) with an aqueous solution of HCL (stomach acid) to produce CO₂ gas to test your engineering design. The reaction of hydrochloric acid and sodium bicarbonate is: HCL + NaHCO₃, one mole of CO₂ gas is produced. Regarding the other products, NaCl dissolves in the water to create a salt solution which occupies only a small portion of the volume inside the bag.
The purpose of this lab is to test substances and to determine the physical and chemical properties of substances.
This experiment involved three steps: synthesis of aspirin, isolation and purification, and the estimation of purity of the final product. The synthesis involved the reaction of salicylic acid and acetic anhydride in the presence of a catalyst, phosphoric acid, H3PO4. When the aspirin was prepared, it was isolated and filtered. The percentage yield of the synthesis was calculated to be 78.42%. The experimental melting point range of aspirin was determined to be 122 -132°C. Due to its wide range, and lower value than that of the theoretical melting point of 136°C, it was
The product obtained had a melting point of approximately 107 °C and a weight of .324 grams. Some of the product would not dissolve in water and so was removed through vacuum filtration, which left .141 g not dissolved in solution. It took 13.2 mL of sodium hydroxide to turn the solution of the product dissolved in water pink. A molecular weight of 138.63 g/mol was calculated from the data. These results indicate that the product was 2-methylbenzoic acid, the Grignard reagent was 2-methylphenylmagnesium bromide, and the unknown bromide solution was 2-methylbromobenzene. Calculations showed that the limiting reagent of the Grignard preparation was magnesium and that the experiment had a 23.13 % yield.
This experiment was conducted under conditions described by Williamson, 2003. To begin, approximately 150 mg of cyclohexanone was placed into a vial. In a separate 10 x 100 mL reaction tube, 1.0 mL of HNO3 was added by pipette, along with a pre-weighed boiling chip. The reaction tube containing the nitric acid was clamped into a sand bath under the fume hood and heated at a low setting. One drop of cyclohexanone was careful added to the nitric acid. The presence of a brown oxide indicated that the reaction had begun, at which point the reaction tube was removed from the sand bath.
Dispense .5 mL water into the already weighed conical vial, replace cap and face insert on its down side.
The purpose of this experiment was to demonstrate how to calculate the molar mass of a volatile liquid using the ideal gas law. By vaporizing a small sample of acetone and condensing it into liquid while measuring temperature, pressure, volume, and mass, the number of moles of the gas substance and its molar mass can be calculated. An accurate calculation of the moles of acetone gas was allowed due to the hole in the foil of the test tube, which ensured that excess oxygen was driven out of the test tube and only acetone gas was left. In order to accurately calculate the mass of the acetone gas, the test tube was placed in an ice water bath to condense the acetone gas into a liquid.
The soda ash form experiment 3 was obtained. A 250 ml beaker was obtained and rinsed.
An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the
An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water
This experiment was performed to determine the heat of neutralization between Hydrogen chloride (HCl) and Sodium hydroxide (NaOH). A temperature probe was used to measure the temperature of the reaction when the base (NaOH) was poured into the acid (HCl). The data was collected on logged on LoggerPro.
In this experiment, the heat neutralization of HCl-NaOH and HNO3-NaOH was determined. To obtain the more accurate data, two trials of each reaction were carried out. For the HCl-NaOH reaction, the heat neutralization was -53.699 KJ/mol for the first trial, -54.363 KJ/mol for the second trial and -54.031 KJ/mol for their average. The percent error calculated in this reaction was 4.74%. Moreover, for the HNO3-NaOH reaction, the heat of neutralization was -55.487 KJ/mole for the first trial, -53.445 KJ/mole for the second trial and -54.466 KJ/mole for their average. The percent error calculated in this reaction was 3.719 %.