Step By Step Synthesis Lab Report

In this Chemistry Lab the main objective is to perform accurate chemical analysis for the quantity of elements and compounds in a sample. There will be a compound made then synthesized. The methods used were acid-base titrations, redox titrations, gravity filtration, and distillation. General conclusions included

2. Write a statement to explain the molecular composition of the unknown solution based on the results obtained during testing with the Biuret solution and each sample solution.

Aspirin Recrysalization Data Table Actual Mass (g) 0.41 Actual MP (ºC) 123-125 Expected Mass (g) 0.533 Expected MP (ºC) 135 Percent Recovery 77% Percent Error 8%

Beran, J. A. Laboratory Manual for Principles of General Chemistry. 9th ed. Hoboken, NJ: John Wiley; 2010

Discussion: In the synthesis of 1-bromobutane alcohol is a poor leaving group; this problem is fixed by converting the OH group into H2O, which is a better leaving group. Depending on the structure of the alcohol it may undergo SN1 or SN2. Primary alky halides undergo SN2 reactions. 1- bromobutane is a primary alkyl halide, and may be synthesized by the acid-mediated reaction of a 1-butonaol with a bromide ion as a nucleophile. The proposed mechanism involves the initial formation of HBr in situ, the protonation of the alcohol by HBr, and the nucleophilic displacement by Br- to give the 1-bromobutane. In the reaction once the salts are dissolved and the mixture is gently heated with a reflux a noticeable reaction occurs with the development of two layers. When the distillation was clear the head temperature was around 115oC because the increased boiling point is caused by co-distillation of sulfuric acid and hydrobromic acid with water. When transferring allof the crude 1-bromobutane without the drying agent,

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.

After 10 minutes the reaction liquid was separated from the solid using a vacuum filtration system and toluene. The product was stored and dried until week 2 of the experiment. The product was weighed to be 0.31 g. Percent yield was calculated to be 38.75%. IR spectra data was conducted for the two starting materials and of the product. Melting point determination was performed on the product and proton NMR spectrum was given. The IR spectrum revealed peaks at 1720 cm-1, which indicated the presence of a lactone group, and 1730 cm-1, representing a functional group of a carboxylic acid (C=O), and 3300cm-1, indicating the presence of an alcohol group (O-H). All three peaks correspond with the desired product. A second TLC using the same mobile and stationary phase as the first was performed and revealed Rf Values of 0.17 and 0.43for the product. The first value was unique to the product indicating that the Diels-Alder reaction was successful. The other Rf value of 0.43 matched that of maleic anhydride indicating some

Once the quantitative analysis indicated that the compound had been correctly identified, it was also our goal to determine methods of synthesizing the compound and to compare the syntheses for cost effectiveness, safety, and potential yield.

The purpose of this experiment was to synthesize t-pentyl chloride from the reaction of t-pentyl alcohol and concentrated HCl. This reaction occurred through an SN1 reaction, a unimolecular nucleophilic substitution reaction. This was a First Order Rate Reaction where the rate of t-pentyl chloride was dependent only on the concentration of t-pentyl alcohol. After the reaction was completed, the products were achieved via 3 liquid-liquid extractions and then after by simple distillation. In the liquid- liquid extractions a solute was transferred from one solvent to another. Then in the simple distillation the miscible liquids or the solution, was separated by differences in boiling points. After this the product was determined through infrared spectroscopy.

Using SN1 reaction mechanism with hydrochloric acid, t-Pentyl alcohol was converted to t-Pentyl chloride in an acid catalyzed reaction. The reaction took place in a separatory funnel designed to separate immiscible liquids. The crude product was extracted by transferring a solute from one solvent to another. The process of washing the solutions by phase transfer was used in order to remove impurities from the main solvent layer. Finally, the crude product was dried with anhydrous Calcium chloride and purified once more by simple distillation technique.

6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.

In this laboratory experiment a synthesis was performed through several separate steps. The purpose of the experiment was to synthesize tetraphenylcyclopentadienone from benzaldehyde and to run reactions on carbonyl containing compounds. There was a total of three steps that led up to the synthesis of the final product, tetraphenylcyclopentadienone. The first step of the experiment was the condensation of benzaldehyde to yield benzoin. Thiamine catalyst along with water and ethanol were added to the benzaldehyde, then NaOH was added until the solution turned yellow. After recrystallization, the product was benzoin. Step two was the oxidation of benzoin to benzil.

After putting the CH2Cl2 to a beaker containing the drying agent anhydrous sodium sulfate, a sticky white solid was recovered.

Based on prior calculations, expected yield for the alkene products was 79.5%. The actual yield was not as high, resulting in a 28.4% yield. Even with this relatively small yield, the reaction still went to completion as indicated by the GC results in Figure 2. This is known because there is no presence of 2-methyl-1-butanol within the GC spectra. Only the two desired alkene products with