Benzoic Acid Lab Report

The original 1.0 gram of the 50/50 mixture of the benzoic acid and benzil contain 0.5 gram of benzil. Thus, from 0.5 gram of benzil, only 0.266 gram of benzil was collected. The percent recovery of benzil was calculated to be 53.2%. This low percent recovery could be due to filtration errors. Some amount of benzil remained on the filtration paper that contained the MgSO4. In order for determining the purity of the

This experiment combined all the knowledge of the previous labs performed throughout the semester. An unknown mixture containing an organic acid or base and an organic neutral compound in nearly equal amounts needs to be separated to its separate components. An understanding of solubility, extraction, crystallization and vacuum filtration is necessary in order to

In this lab, liquid-liquid extraction was performed to isolate a mixture of benzocaine and benzoic acid. 2.0107 grams of the mixture was first weighed out for the trials. When HCl was added to the mixture for the first acid extraction of benzocaine, an emulsion formed during inversion and venting that prevented a defined separation of the two layers. 8 mL of water was therefore added before continuing the extraction. The addition of NaOH then turned the top aqueous layer basic, indicated by the pH strips that turned blue when tested. A vacuum filtration isolated 0.29 grams of benzocaine and a MelTemp apparatus measured the crystal’s melting point ranges to be 85.1C-87.4C. For the base extraction of benzoic acid, the aqueous layers were retrieved

As indicated in Table 1, each of the given substances for this lab were soluble in ethyl acetate. However, the solubility results varied based on the structure of each tested compound. 4-bromoacetanilide and fluorene are both insoluble within solvents of HCl and NaOH. Fluorene will stay soluble within the organic layer since its is a purely made of carbon and hydrogen. 4-bromoacetanilide will act similarly given its nonpolarity from balanced branches and lack of acid/basic characteristics. 4-nitroaniline and 2,5-dichloroaniline travel solubly into the HCl/H2O solvent when added to the separatory funnel, yet form a precipitate after a highly concentrated NaOH is added. Both 4-nitroaniline and 2,5-dichloroaniline are slightly basic organic compounds, and when an acid (HCl) is added a proton will transferred to make them ionic. In their ionic state, both compounds become water-soluble. When NaOH is added to 4-nitroaniline and 2,5-dichloroaniline, it removes the proton causing the compounds to become insoluble in water once again. The same concept can be applied in an opposite fashion to the acid organic compounds of 3-chlorobenzoic acid and resorcinol; both become water-soluble when they lose a proton after mixed with NaOH. They go back to their water insolubility if you add an acid to donate a proton back to 3-chlorobenzoic acid and resorcinol. Therefore, after completing this lab,

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.

Samples of benzophenone, malonic acid, and biphenyl were each tested with water, methyl alcohol, and hexane. Benzophenone was insoluble in water as it is nonpolar while water is highly polar. Benzophenone was soluble in methyl alcohol, dissolving in 15 seconds, because methyl alcohol is intermediately polar as benzophenone is nonpolar. Methyl alcohol is polar but not as much as water. Thus, the nonpolar benzophenone was soluble in methyl alcohol. Benzophenone was partially soluble in hexane because hexane is nonpolar as is benzophenone. Thus, benzophenone was dissolved in hexane. Malonic acid was soluble in water because both malonic acid and water are polar. It took 25 seconds for malonic acid to dissolve in water. Malonic acid was soluble in methyl alcohol because malonic acid is polar and methyl alcohol is intermediately polar, allowing malonic acid to dissolve in the methanol in 15 seconds. Malonic acid was insoluble in hexane because hexane is nonpolar while malonic acid is polar. Biphenyl was insoluble in water as water is highly polar whilst biphenyl is nonpolar. Biphenyl was partially soluble in methanol which is intermediately polar whilst biphenyl is nonpolar, allowing it to dissolve a little. Biphenyl was soluble in hexane because both biphenyl and hexane are nonpolar molecules. Biphenyl dissolved in hexane in 10 seconds.

6. The solubility of the solids were tested using a micro tray, by placing them in water and oil to observe their polarity,

Objective: The objective of this experiment is to use acid-base extraction techniques to separate a mixture of organic compounds based on acidity and/or basicity. After the three compounds are separated we will recover them into their salt forms and then purify them by recrystallization and identify them by their melting points.

Experiment 4A: Determination of a Partition Coefficient for Benzoic Acid in Methylene Chloride and Water, and Experiment 4B: Solvent Extraction I: Acid-Base Extraction Using the System Benzoic Acid, Methylene Chloride, and Sodium Bicarbonate Solution

The litmus test might have contributed to a significant loss of the precipitate, but only one instead of multiple tests were performed to see if the reaction mixture was acidic enough. Given the carefully controlled experiments and the 90% yield, it can be deemed that the methods used to perform the experiments are full proof and performed as immaculately as possible.

organic compound to dissolve (increase in entropy), a decrease in heat will then allow that

After the initial mixture has refluxed, 9.11 grams of benzophenone was dissolved in 100 mL of anhydrous ether in a beaker and was then transferred into the separatory on the reflux apparatus. This solution was then added to the Grignard reagent at a drop wise rate while stirring. After the benzophenone was added, the mixture was then refluxed for 15 minutes on a heating mantle.

The purpose of this experiment was to use solvent extraction techniques in order to separate a mixture consisting of a carboxylic acid (p-toulic acid), a phenol (p-tert-butylphenol), and a neutral compound (acetanilide). Extraction is the process of selectively dissolving one or more of the compounds of a mixture into an appropriate solvent, the solution that contains these dissolved compounds is called an extract (Manion, 2004).

The purpose of this experiment is to separate a mixture of salicylic acid and naphthalene using extraction, recrystallization and sublimation techniques. Extraction is the separation of compounds from a mixture based on their relative solubilities in different solvents. Sublimation is the process of separation by which a substance transitions from the solid phase into the gas phase, skipping the liquid phase. Recrystallization involves dissolving a substance in an appropriate solvent then crystallizing it as it cools (impurities remain in solution). The melting points of the substances were determined in order to assess their purity and the percent recovery of pure naphthalene and salicylic acid were calculated. According to the results, the melting point of pure naphthalene was between 86°C -89°C range, whereas for pure salicylic acid was 167°C -170°C. Both determined melting points were higher compared to the literature value of 80.26°C and 158.6°C for pure naphthalene and salicylic acid respectively. Lastly, the percent recovery for pure naphthalene and salicylic acid were 17.7% and 71.2% accordingly.

Based on Table 1 for experiment Part A which is the solubility of solid compounds, it resulted in the mixture of solution between benzophenone and water were insoluble. Water is highly polar meanwhile benzophenone is only slightly polar due to its carbon and oxygen is bonded by double bond. The fact that benzophenone is hydrocarbon, further addition of carbon atoms to the chain will decrease the polarity. The pi bonds in benzophenone also allow for greater Van Der Waals forces. Next, benzophenone and methanol were partially soluble because they have equivalent polarity. Benzophenone and methanol both possess an electronegative oxygen atom[2] that accounts for their related polarity and solubility. Benzophenone and hexane were partially insoluble too because hexane is a non-polar. Two non-polar compounds react with each other with the same polarity will not fully ionizes each other completely resulting to the partially soluble end result.