In this experiment, extraction was used as a separation technique to separate the acid, base, and neutral compounds. In extraction, two immiscible solvents with opposite polarities are used to dissolve different parts of the solute with different polarities, so they form two distinct liquid layers. In this experiment, methanol, an organic solvent, and an aqueous solution were used as the two immiscible solvents. The extraction solvent must also be capable of dissolving one of the mixture components. While initially it seems as though methanol, an organic solvent would be incapable of dissolving a polar acid or base, the conjugate of the acidic and basic compound will dissolve in methanol. The conjugate acid and base were obtained by adding …show more content…
All the data used for analysis of the neutral compound was received from Andrew ______, since there was not enough sample left to perform MP analysis after the recrystalization step. Since the ranges for these melting points are larger than the ranges observed for the recrystalization product, it can be inferred that these samples contained impurities, and also possibly traces of ethyl acetate or water, depending on the solvent they were in. These melting points can also be used to make a rough guess about the identities of these compounds, as seen later in this report. According to the MSDS pages for salicylic acid, 4-nitroaniline, and p were 159, 148.5, and 101 respectively. The melting points for the acidic and neutral compounds were hence too low, and the melting point for the basic compound was too high. The errors in the acidic and neutral compounds can be explained by impurities in the crude product, along with the presence of the solvents, ethyl acetate and water, which disturbed the stability of the compounds, and led to lower melting points over a larger range. The abnormally high melting point of the base may have been observed due to improper separation of the acid and base solutions in the separation funnel. Some of the acidic compound may have entered the basic solution and reacted with the base to form a high melting point salt, making the melting point of the base appear abnormally high. The Mel-Temp was also turned on a high setting accidentally, so it is possible that the temperature rose too quickly to get a good reading of the melting
After adding the acetic acid and hydrobromic acid to the solution, and heating and recrystallizing the solution, the product triphenylmethyl bromide was created and had a mass of 0.103 g. The theoretical yield was calculated by determining the limiting reagent in the reaction. The triphenylmethanol was the limiting reagent in the reaction. The total amount of mass from the triphenylmethanol was converted to moles by using the molar mass of the triphenylmethanol. The amount of moles was then converted into grams to determine the theoretical yield, 0.125 g. The percent yield was then calculated by dividing the actual yield by the theoretical yield and multiplying the result by 100%. The percent yield was 82.4%.
The boiling point range of Unknown 30A was 65.0 °C-67.2 °C. The two degrees difference in the boiling point range indicated that there were very few impurities presented in the liquid. The theoretically possible identities of the unknown were primary amines that contained higher boiling points than the range because of the higher altitude lab. However, sec-butylamine, with a boiling point of 63 °C, was included as a possible identities because it was only two degrees off of the range. Therefore, it was too early on in the experiment to eliminate a potential identity that was very close to the range.
The three-component mixture was separated through the isolation of each individual component. The isolation process began with o-toluidine, which utilized the addition of hydrochloric acid, sodium hydroxide, and dichloromethane—to the mixture—for the formation of an organic layer that contained pure o-toluidine. Then, the addition of sodium hydroxide and hydrochloric acid to the remaining mixture resulted in an organic layer, which contained pure benzoic acid precipitate. Finally, anhydrous magnesium sulfate and methylene chloride were added to the remaining mixture of anisole, which resulted in a pure anisole because it removed all residual water and boiled off excess methylene chloride used. The percent recovered from extracted anisole, benzoic
Dehydration of 2-Methylcyclohexanol Sura Abedali Wednesday 2:00 PM January 31, 2018 Introduction: Dehydration reactions are important processes to convert alcohols into alkenes. It is a type of elimination reaction that removes an “-OH” group from one carbon molecule and a hydrogen from a neighboring carbon, thus releasing them as a water molecule (H2O) and forming a pi bond between the two carbons1. In this experiment, 2-methylcyclohexanol undergoes dehydration to form three possible products: methylenecylcohexane, 1-methylcyclohexene, and 3-methylcyclohexene in a Hickman still apparatus. Adding 85% Phosphoric Acid to protonates the “-OH” group, turning it into a better leaving group and initiating the dehydration reaction.
The powder on the filter paper could've fell and this caused it to have a smaller percent purity, percent yield and also cause a lower absorbance and concentration of pure ASA. Another error would be not using a properly dried sample for the pure ASA in part C when making the crystals, this could have cause tye percent yield error. This would make a lower melting point. To prevent this from occurring next time there could be a dry sample that is completely dry and this would not alter the mass of the sample and this would make the solution have a more
9. The melting point range was lower than the given range of the anti-addition product by 2 degrees Celsius. This could have been due to impurities in the product. A likely cause could have been water that still remained in the product after recrystallization (the product shifted upward during melting point analysis due to evaporation). Since water has a low melting point, it could have lowered the melting point range of the product.
3. To purify and identify the product, recrystallization is used in order to purify the product, then melting point and TLC techniques are used to identify the product. Theory 4.
The purpose: To investigate the rate of the reaction between Magnesium and different concentrations of HCL. Hypothesis: If the concentration of HCL increases, the rate of the reaction between HCL and Magnesium decreases. Scientific Explanation:
INTRODUCTION A gas chromatograph (GC) can be utilized to analyze the contents of a sample quantitatively or in certain circumstances also qualitatively. In the case of preparative chromatography, a pure compound can be extracted from a mixture. The principle of gas chromatography can be explained as following: A micro syringe is used to inject a known volume of vaporous or liquid analyte into the head or entrance of a column whereby a stream of an inert gas acts a carrier (mobile phase). The column acts as a separator of individual or chemically similar components.
CLAIRE MUNTING 29/01/2018 Criterion C EFFECTS OF SURFACE AREA OF CALCIUM CARBONATE UPON RATE OF REACTION Calcium Carbonate Chips 1 Introduction: Within the current investigation, the effects of the surface area of Calcium Carbonate (CaCO3) in combination with Hydrochloric acid (HCl) upon its rate of reaction. CaCO3, commonly referred to as limestone, is an organic substance and is, in a sense, the crystallised “carbonic salt” of the element, calcium2. In addition to being a salt, the pH level of Calcium Carbonate is 9.91, and it is therefore, a basic substance, due to the fact that it is comprised of a pH level higher than 7, which is neutral3. HCl, however, is the bodily acid found in the stomach of human beings.
Separation of compounds is based on the stationary and mobile phase. Mobile phase is the solvent and the stationary
This is coherent with the idea that adding p-xylene into methyl acetate as a mixed solvent could lead to enhance the values of capacity of extraction and selectivity of acetic acid against water. This result showed p-xylene is powerful enough to be considered as the feasible solvent when mixed with methyl acetate. Likewise, the use of p-xylene
This verified the formation of the major products. Overall, one can say that the experiment was
The different rates between desorption and adsorption are applied in the chromatography methods for separation of mixtures. In
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.