Recrystallization Synthesis

The purpose of this lab was to be able to use physical characteristics to determine the identity of an unknown compound. The data from this experiment classified aluminum as metallic; ascorbic acid, paraffin, palmitic acid, sucrose, graphite, and water as molecular; sodium chloride as ionic. In order to determine this, 3 tests were conducted. The first test was to test the conductivity of each substance at room temperature. In this test, only graphite and aluminum conducted.

Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.

Temperature is important, since above 250C° and below 50C virtually no crystallization occurs. Around 14°C is the optimum temperature for rapid crystallization, but also the presence of solid particles (e.g. pollen grains) and slow stirring result in quicker crystallization. Usually, slow crystallization produces bigger and more irregular crystals. During crystallization, water is freed.

There were a few steps in the experiment that may have contributed to impurities in the unknown crystals. In the beginning of the experiment, the column with alumina was used to filter the methanol/unknown mixture into a vial. It was important to add the mixture after methanol was added to the column and was still above the top

3mL of the liquid in each of the vials were added into cuvettes and measured in the spectrophotometer. Before each time point the photo spectrometer was zeroed using a cuvette with 3mL of distilled water. If any of the results were considered unusual the machine was zeroed again and the sample was retested. The results from the spectrophotometer test were recorded in a table. The experiment was repeated six times to gain a sample size of six.

The following lab period the solid was weighed (0.0483 g) and percent yield was calculated (65.5%) with the limiting reagent being tetraphenylcyclopentadienone. The melting point was determined. The first melting point was 204-204.9 °C and the second melting point was 215.6-215.9°C. Finally, an infrared spectroscopy was obtained for the

Pages 96-98 in Chemistry 110 Lab Manual. Wilfrid Laurier University, ON, Canada. Abstract: The purpose of this experiment was to determine the level of purity by using the values for melting point and absorbance and chemically synthesizing aspirin by using phosphoric acid as a catalyst.

Glacial acetic acid and acetic anhydride were added to the mixture while refluxing, which converted the lime colored solution into a clear mixture. The flask was cooled in an ice bath and the solution

Abstract: The purpose of this experiment was to identify given Unknown White Compound by conducting various test and learning how to use lab techniques. Tests that are used during this experiment were a flame test, ion test, pH test, and conductivity test. The results drawn from these tests confirmed the identity of the Unknown White Compound to be sodium acetate (NaC2H3O2) because there were no presence of ions and sodium has a strong persistent orange color. The compound then will be synthesized with the compounds Na2CO3 and HC2H3O2 to find percent yield.

Trial #2 and Trial #3 were used to determine the freezing point of an aqueous solution. The “Unknown C” was used to create the aqueous solution. For Trial #2, 2.0019 grams of “Unknown C” were weighed and dissolved into the 11 dram vial. Once dissolved, the 11 dram vial was submerged into the ice bath, and the Vernier temperature probe was immersed into the 11 dram vial as well. Once the temperature of the aqueous solution reached 10°C, the temperature was recorded every 10 seconds.

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 solvent was removed using a rotary evaporator. The melting point was estimated. The obtained mass of caffeine was measured. The percentage yield based on the amount of tea originally used was calculated. 2) Purification of caffeine by sublimation

In Experiment One we will be recrystallizing Benzoic Acid from water. In Experiment Two we will be recrystallizing Benzoic Acid using a solvent pair made up of Methanol and Water. The Seven step process of recrystallization consists of adding a solid organic substance into a solvent, then dissolving the chosen solute, decolorizing the solution, filtering solids, then recrystallize the solute by slowly cooling

Introduction: In this lab, of water in a hydrate, or a substance whose crystalline structure is bound to water molecules by weak bonds, is determined by heating up a small sample of it. By heating, the water of hydration, or bound water, is removed, leaving only what is called an anhydrous compound. Based on the percent water in the hydrate, it can be classified as one of three types: BaCl2O ⋅ 2H20, with a percent water of about 14.57%, CuSO4

When a solid dissolves in a liquid, it then changes its physical state (from solid to liquid) by melting. Heat is needed to break the bonds holding the molecules in the solid together and at the same time; heat is given off during the formation of new bonds between solute and solvent. Results Table1. Results for titration of benzoic acid with NaOH at 20◦C V(NaOH) ml V(C_6