Extraction of Benzoic Acid Essay

There are various techniques to separate a mixture of compounds from each other. One of the commonly used way to isolate compounds from a mixture of two compounds is called extraction. This method of extracting two compounds from each other relies on the different solubility of the compounds in two different solvents.

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 the first acid extraction of benzocaine, the compound was dissolved in the organic solvent of dichloromethane. When the mixture was shaken with HCl, benzocaine’s amine group gained a proton and became more soluble in water than dichloromethane. This allowed the newly formed hydrochloric salt to migrate to the aqueous layer. However, the addition of NaOH to the acidic aqueous layer regenerated benzocaine by deprotonation, making it insoluble in the aqueous layer. The precipitation of an ionic salt was therefore recovered by vacuum filtration and had a tested melting point range of 85.1C-87.4C compared to 88C-90C, the literature melting point of benzocaine. The similarity in melting point ranges, but low percent yield of 30.37% proves that the extract was somewhat successful. Lower yields may be the result of spillage performed in the lab. In the second basic extraction, the organic layer now included benzoic acid and benzamide. When treated with NaOH to deprotonate benzoic acid, the newly formed sodium benzoate transitioned to the aqueous layer as a sodium salt. Benzoic acid is regenerated once again after the addition of HCl and became insoluble in the aqueous layer after protonation. Its precipitation was then filtered out for a 65.87% recovery. Compared to its literature melting point of 122.41C, the resulting 120.9C-123.5C melting range of the sample also supports the accuracy of the separation due to its similarities and high percent yield. In conclusion, the usage of base and acid liquid extraction was mostly successful in this experiment because it was able to efficiently and properly isolate the impure mixture into two separate components of benzocaine and benzoic acid. By performing the techniques of extraction and vacuum filtration, the similarities between literature and tested

Me and my lab partner, obtained a mixture of a un known proportion from the instructor and then flow the guide line in our lab manual to separate the mixture by applying the separation method motioned in our lab manual pages 33-40 . In this experiment, the separation methods were decantation,

There are millions of different organic compounds. Most of them are found in mixtures and in order to achieve a pure form they need to be separated, isolated, and purified. However, there are endless numbers of possible mixtures, which make it impossible to have a pre-designed procedure for every mixture. So chemists often have to make their own procedures. The purpose of this experiment was to prepare the student to the real world by them designing their own procedure which will help them understand the techniques of separation and purification better. The goal was to extract two of the components of the

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.

The objective of this extraction experiment was to achieve a comprehensive understanding, as well as master the practice, of the technique of separating various individual components of a compound.

In order to isolate benzoic acid, benzocaine and 9-fluorenone, each component needed to be separated from one another. All three compounds began together in one culture tube, dissolved in methylene chloride and formed into a homogenous mixture. In this culture tube, two milliliters of aqueous three molar hydrochloric acid was added, which immediately formed two layers, the top acidic aqueous layer was clear in color and contained benzocaine, and the bottom organic formed was yellow and contained benzoic acid and 9-fluorenone. Benzocaine’s amino group is protonated by the aqueous layer hydronium. This protonation forms the conjugate acid of benzocaine, benzocaine hydrochloride. Thus, the conjugate acid, benzocaine hydrochloride is a salt in which is soluble in water and furthermore can be isolated from the organic mixture. When testing out the pH levels in benzocaine, the pH test strip was dark blue in color, indicating a pH level of around 5 to 7. When isolating benzoic acid, two milliliters of aqueous three molar sodium hydroxide was added, which deprotonates the carboxylic group in benzoic acid, forming its conjugate base, sodium benzoate. As with benzocaine hydrochloride, sodium benzoate is a water soluble ionic salt in the aqueous layer that can then be separated from the bottom organic layer containing the 9-fluorenone. The pH test strip was a vibrant red for benzoic acid, indicating a pH of 2. Now the 9-fluorenone is left, deionized water is added to remove any excess

Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.

In the beginning of this experiment, our TA added water, salt, and 75/25 hexane/acetone to spinach leaves to a blender and blended the mixture to assume equal amounts for each group and to avoid erros if each student had to do the blending. The addition of the water to the mixture allowed the it to separate into a distinct organic layer after being run in a centrifuge, which was available to be collected at the top of the centrifuge. Salt reduces solubility, which will force the organic parts of the mixture (the desired pigments for example) to separate into the organic layer at the top. Lastly, 75/25 hexane/acetone is added because this is a moderately polar solvent and will useful for both the non-polar and polar pigments present within the spinach leaves. A mixed solution of hexanes and acetone must be used because acetone is very polar, while hexane in very non-polar, and the spinach leaves contain both non-polar and polar pigments in them that are important in the extraction and for further analysis. The mixture was placed in the centrifuge so the solids in the mixture (mostly cellulose) could be separated from the liquids into separate distinct layers for further extraction and testing. In the tube, the organic substances separated into the top layer, whereas the water layer remains at the bottom of the tube below the solid layer made up of mainly cellulose.

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.

The purpose of this experiment is to familiarize oneself with the general procedures determining a partition coefficient at the microscale level and learn in weighing milligram quantities of materials on an electronic balance, the use of automatic pipets, the use of transfer pipet, and the use of a vortex mixer. Also, to familiarize oneself with extraction

The eluting solvent passed down the column by the gravity and an equilibrium was established between the solute absorbed by the absorbent (silica gel in this experiment) and the eluting solving flowing down. Since the components in the sample had different polarity and they interacted with the stationary phase and the mobile phase differently, the components would be carried by the solvent to a different extent and a separation of the components could be achieved.

In the separating funnel, a heterogeneous mixture was formed: resulting in an organic layer (top) and a solvent layer (bottom). This effectively allowed the draining of the solvent, in order to isolate the organic layer, the impure ester (1-pentyl ethanoate)

Separating a mixture can be either very simple, or greatly complex. For example, a heterogeneous mixture, such as a bowl of different types of candy, can be easily sorted by the color, size, or shape of the individual candy. But homogenous mixtures, such as air, steel, or sugar water, takes sometimes complicated procedures to break the mixture or solution down into its original form. Separating mixtures can be done by using the differences in their properties, such as the color, size, shape, boiling point, or density of a specific element (Brown et al., 2014, p. 13). There are many types of methods to separating mixtures, which includes sublimation, crystallization, and simple or fractional distillation.