The mixed melting point of the unknown with the benzene acid was 107. -109. OIC and with the 2-decontaminated was 127. 5-128. ICC so the compound must be 2- decontaminated. Introduction: This experiment was conducted in order to explore the methods of rationalizations and in order to determine the melting points of various solids. Rationalizations is to purify a solid by allowing it to recitalist out the solution. The impurities stay in solution while the desired solid precipitates out. You have to dissolve a solute in a hot solvent and, then recitalist the solute out of the cooled solvent.
The formation of concentrated, pure crystals is possible n this rationalizations process if the appropriate cooling rate is applied to the solute and solvent mixture. Consequently, a purified, solid compound would be produced. Rationalizations involves dissolution of a solid in a solvent at elevated temperatures and the reformation of the crystals as the solution cools, allowing for impurities to remain in the solution. Once a solid has been rationalized, it is important to determine the purity of the rationalized solid.
Experimental Procedure: Cautious: – Vapors generated in this experiment are nasty. Carry out this experiment in the hood. Use caution when working with hot plates and hot solutions: it is easy to burn oneself when pouring boiling water or if one’s solution bumps. Procedure: part A: Dissolve the compound in a minimum of boiling water. Skip the gravity filtration step (no insoluble impurities are present). Allow the solution to slowly cool to room temperature. (At least minis) Cool the solution in ice for 20 minutes. Collect the crystals by vacuum filtration.
Place your crystals in an oven at 90 degree Celsius on a watch glass to dry for at least 20 minutes. Part B: Repeat on a 2nd sample. Repeat the procedure above Dissolve the compound in mall of water. Dissolve the compound in a minimum boiling water and then boil the solution long enough to reduce its original volume to half. Allow the solution to cool to room temperature for only one minute and then cool in ice for 20 minutes. Allow your second set of crystals to dry in an oven for 90 degree Celsius for at least 20 minutes.
Determine the melting point of the original impure sample. Determine the melting point and yield of both sets of purified crystals. Report your results in tubular form. Submit both sets of crystals in labeled vials. Results: Solvent Physical State Molecular Weight (g/mol) Melting Point (C) Benzene Acid Unknown B Liquid 34. Egg ICC Benzene Acid Unknown B quid 24. Egg ICC The table explains my two benzene acid of unknowns B and B. Firsts take the plate and weighed it as 32. Egg, the paper was . Egg and 1. Egg of acid was added to the total of 34. Egg.
By taking the benzene acid with the instructions to prepare the unknown for the moderate amount of H2O (million) slowly. After it iced for 20 minutes the crystals were ready to collect in the filtration. Then, it was placed in the oven for at least 20 minutes, and then got its weight and the rascals were ready to be placed in the digital scales to be placed in the dig melt to find its melting point, which was ICC. With the second sample of benzene acid B the plate weighed at 23. Egg, the paper was . Egg and 1. Egg of acid was added and the total weighed out to be 24. G. Using this sample the guidelines were to perform a moderate amount of H2O (ml/ml) quickly. After it iced for 20 minutes the crystals were ready to collect in the filtration. Then, it was placed in the oven for at least 20 minutes, and then got its weight and the crystals were ready to be placed in the digital scales to be placed in the dig melt to find its melting point, which was ICC. Discussion: During the cold filtration, the water soluble impurities that might dissolve in water which was filtered out through the suction filtration.
However, some of the impurities might be trapped on the surface of the benzene acid crystals, so a small volume of ice-cold water should be used to wash the benzene acid crystals to dissolve the particular impurities. The crystal was dried in the oven at 100 co. A fresh piece of filter paper can be used to place under the filter paper with benzene acid crystals. Benzene Acid unknown B melting point range from ICC-ICC and the unknown benzene acid of B ranged from 122. C-ICC. The purity of a crystal can be determined by its melting point.
A narrow range of melting point indicates high purity of the sample, otherwise broad range of melting point indicates the presence of impurities in the crystal. The melting point of the recovered benzene acid obtained experimentally is 126 co. Compared to the pure benzene acid with ICC of melting point, the purity of the recovered benzene acid is very high with 98. 36%. Questions: Tabulate the part B results you obtained and those of at least three others who carried out different modifications.