Nahco3 Synthesis Lab Report

12.5 cm3 of 0.9992 M sodium hydroxide solution was transferred to a 250 cm3 volumetric flask by burette and de-ionized water was added to the mark. The flask was shaken to ensure homogeneity of the solution.

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

Significance In the experiment, mass and the number of moles of a particular vapor will be known which will help to identify the molecular weight of the substance. Design and Methods Reagents  Benzene  Unknown Liquid  Distilled water Apparatus  Erlenmeyer flasks  Analytical balance  Thermometer  Beaker  Clamp  Iron stand  Iron ring  Wire gauze  Bunsen burner  Stopper Procedure The following procedure was done separately on benzene and the unknown liquid. A. Preparation of the Apparatus Both Erlenmeyer flasks were cleaned and were weighed using the other as a tare to minimize weighing errors due to the change in temperature and moisture forming on the surface of the flasks which will occur on both flasks, so that in weighing, the tare simply balances that of the weighed flasks. Ten mL of the test liquid was placed in one of the flask, and the flask was immersed in a beaker of water so that only the neck is above the surface. It was secured with a clamp and was tilted slightly so that the round bottom is the lowest part, and the liquid in the flask is clearly seen. B. Volatilization of the Liquid

To a 5 mL conical vial with a spin vane, 5-nitro-2, 3-dihydrophthalazine-1, 4-dione (.151 grams) was added. Next, sodium hydroxide (2 mL, 3M) was added to the conical vial and stirred until a reddish brown color was obtained. The addition of sodium hydrosulfite (.254 grams) followed, and the sides of the conical vial were

While the reflux heating of procedure A was completing, procedure B allowed for the addition of the t-pentyl alcohol of 2-methyl-2-butanol to the solvent-nucleophile solution in a separatory funnel. After the two were shaken and mixed, the separatory funnel was allowed to sit, which let the solution develop the alkyl halide layer. This separation process involving the separatory funnel shaking was important as it allowed the mixture to develop distinct two layers and made for a simple extractionD. The lower, less dense aqueous layer that contained the sulfuric acid and water was drained off and the less dense alkyl halide upper layer was transferred into a beaker that contained solid sodium bicarbonateF. The solid sodium bicarbonate added during

20.34mL of diethyl malonate was added to the solution via the separatory funnel over a period of about fifteen minutes. Next, 35mL of EtOH and 14.5mL of n-BuBr were added to the mixture respectively. The solution was refluxed for 10 minutes using a heating mantle and then cooled on ice. The above mixture was later poured into 200ml of water and then transferred to a 500mL separatory funnel.

This experiment introduces separation and purification methods used in research quite frequently. These methods include hot vacuum filtration and recrystallization to purify a crude sample of acetanilide containing two impurities. Recrystallization is a very common method that is used to purify solids. This process dissolves a crude solid with impurities in a mildly boiling solvent, and cooling down the mixture afterwards for crystals to reconstruct themselves in solution. This method allows impurities to separate and remain in solution as precipitate or remain uniform in solution. Solids are more soluble in hot solvents than in cold ones, allowing maximum dissolution for proper separation and subsequent crystallization to occur. After purifying the compound, the melting point is determined using the Mel-Temp technology to compare to the written melting point to see how pure the sample truly is. The proper steps of recrystallization include selecting a solvent that fits the characteristic of all the components, water in this experiment. Then, dissolving a crude sample in the chosen solvent (at or close to the solvent boiling point), forming solid in the solution as cooling takes place, using vacuum filtration to isolate the purified solid, ridding the crystals of all impurities through drying. In this experiment, recrystallization allows purification of 150 mg of crude acetanilide. Hot vacuum filtration is a process used. The process requires using a filter flask, Pasteur

In this experiment a suitable recrystalising solvent will be selected. Filtering, separating and purifying acetanilide from a solution by recrystallisation. The weight and percentage recovery of the recrystallised acetanilide will be calculated.

The apparatus was set-up in fume hood. After adding 5ml of acetic anhydride and five drops of 85% phosphoric acid into 50ml Erlenmeyer flask which contained 2.001g salicylic acid, the flask was heated on a hot plate (75℃ ) for 15 minutes while stirring the flask’s content. A butcher funnel was then set-up for filtration of the flask’s content.

The method used in this experiment is titration, which is a method used to measure the amount of an analytical reagent necessary to react with a sample. Concentrated hydrochloric acid is a solution containing about 35 % HCl by mass, but varies from batch to batch, due to the liquid fuming so much it becomes lost while transferring it from one place to another. The standardization of HCl and the Analysis of Na2CO3 can be determined by determining how much of the sodium carbonate solution is required to neutralize the hydrochloric acid, which we can calculate at a very precise value with the concentration of hydrochloric acid through titration, by preparing a solution of HCl then using it to titrate a base with a known purity percentage and mass, giving us the molarity. Once the average concentration has been discovered, we then use that precise value to titrate and determine the alkalinity of sodium carbonate in the unknown samples.

The NaOH solution was prepared first by gathering one gram of the NaOH pellets to prepare 250 mL of 0.1 M NaOH solution. The pellets were weighed out on a top loading balance. Then the 100 mL of deionized (DI) water was mixed with the pellets with a stir plate and stir bar in a beaker. The solution was transferred to a 250 mL volumetric flask pre-rinsed with DI water. More DI water was added to reach the 250 mL mark on the flask. Then the flask was inverted and then shaken gently to distribute the solution evenly. This solution was then transferred to a plastic bottle pre-rinsed with DI water. It was then labeled with the identity and concentration of the solution

This was set aside for a water bath later in the experiment. 13.8 g of salicylic acid followed by 14mL of acetic anhydride is combined to a 125mL Erlenmeyer flask. Eight drops of concentrated H2SO4 was added to the Erlenmeyer flask that housed the salicylic acid and acetic anhydride. The contents were then gently swirled and transported to the hot water bath created earlier. The heat from the water bath and occasional mixing of the contents quickly dissolved the powder contents. The flask was then removed and combined with 40mL of cold distilled water. The flask was then placed into an ice bath to create a slush-like substance. A vacuum filtration system was assembled and the slush was washed three times with distilled water. The product was left to dry in lab drawer for seven

The experiment utilized acid-base reactions (Table 1) to manipulate the extraction and isolation of the three components. The first component that was extracted from the three component mixture was the base m-Nitroaniline. HCL was added to the three-component mixture, the base m-Nitroaniline separated from the ether, benzoic acid, and naphthalene. After this acidic extract was separated into an Erlenmeyer flask along with the water extract, the acidic extract was converted back to m-Nitroaniline by adding NaOH until the solution became alkaline. Following vacuum filtration the remaining compound was observed as yellow powder. Benzoic acid was then separated and extracted after adding NaOH. HCL was then added until the solution became acidic.

A solution of sodium hydroxide (3g) in water(30ml) an ethanol (25ml) was prepared and stirred in a 250ml conical flask that was maintained at 20-25ₒ in water bath. Benzaldehyde and A.R acetone were mixed and divided into two portions. The accurate masses of the starting materials, benzaldehyde and A.R acetone are shown below.

A mixture of 2 organic compounds was separated using recrystallization and purified. Melting Point Determination was the method used to identify the 2 organic compounds and cross-checking the experimental results obtained with a list of possible organic compounds showed that the Neutral Compound was Dibenzalacetone and the Acidic Compound was o-Chlorobenzoic acid. Verifying the identified compounds via their appearances with references further validated the experimental results.