Discussion:
There are numerous ways of isolating and purifying a substance, and an investigation of the differences of each procedure were performed. In two different procedures, lead nitrate and potassium iodide were used to isolate and purify pure solid lead iodide, and the differences in the limiting reactant and solid lead iodide was observed. The amount of solid lead iodide was calculated by the measuring the mass of which the solid lead iodide was created in before and after the purification of solid lead iodide.
The purification and isolation of solid lead iodide was achieved in two different process with different results. In the evaporation collection, the solid iodide was created by adding heat to the water base solution of lead
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In the evaporation collection, potassium nitrate was left behind in the casserole dish. If no potassium nitrate was present the percent yield would be closer to 100% yield, but this is not the case. The percent yield for the evaporation collection was 144% yield which is not close to 100% yield.
The evaporation collection procedure was able to achieve over 75% yield with a percent yield of 144%, while the vacuum filtration was unable to achieve the goal with only 56.9% yield. The evaporation collection was able to achieve the 144% yield by carefully transferring all of the liquid from the test tube to the casserole dish with accuracy and using distilled water in the procedure.
Based on the percent yields, the evaporation collection technique would be the best option since it achieved 144% yield, which is over the 75% yield goal. Although the evaporation collection attained a better percent yield, the vacuum filtration produces a purer lead iodide because the potassium nitrate is filtered out of the Buchner funnel, while in the evaporation collection keeps the potassium nitrate in the casserole dish.
In this experiment, there are two different systematic errors to consider. In the evaporation collection, the casserole dish that was used had an uneven edge which could have allowed some of the solution, which contained lead
The lead in the environment is formed naturally in the earth’s crust mainly as Lead Sulphide. The main exposure channels of lead entering the environment through atmospheric lead is predominantly from automobile emissions. Other lead exposure routes include lead-acid batteries, paint chips, fertilizers, utilized ammunition, pesticides, and other industrial byproducts. The means of conveying lead from key emission sources is mainly through the air. Concerning the sources of lead in drinking water, normally lead reaches into the residents’ water after it is channeled from their water treatment plant or the wells. To be more precise, the source of lead in people’s water supply largely emanates from their households’ pipes or lead solder from plumbing. The most typical cause of the lead formation is from the corrosion reaction by the lead pipes or solders and the water. The acidity as a result of the low pH, dissolved oxygen, and little mineral contents in the water are main reasons of the corrosion. The lead amounts in the water become high if the water spends a long duration of time stagnated inside the old pipes.
The purpose of this lab is to separate a mixture and determine the percentages of each of the ingredients. Each substance will have a different boiling point due to its intrinsic properties and from that, we will be able to determine the purity of different products as we evaporate off the next level of product.
Distillation. Transfer the clear liquid to a dry 25-mL round-bottom flask using a Pasteur pipet. Add a boiling stone and distill the crude t-pentyl chloride in a dry apparatus. Collect the pure t-pentyl chloride in a receiver cooled in ice. Collect the material that boils between 78°C and 84°C. Weigh the product and calculate the percentage yield.
3. Turned off the laboratory burner and observed the properties of the product in the evaporating dish.
Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.
Lead poisoning is one of the global burden and need to be focused a lot on preventive strategies.
First we placed the evaporating dish on the wire to preheat for 3 mins. Next, we used tongs to transfer the evaporating dish and allowed 5 mins to cool and took the mass afterwards. After that, we added approximately 2g of MgSO4 crystals to the evaporating dish and found the mass. We then placed the dish on the burner for 10 mins, allowed it to cool found the mass. Next, we heated the dish again for 7 mins, allowed it to cool and found the mass. Lastly we burned until there was a constant
All the controversy about the lead problems in Flint, Michigan has stirred up questions across the country. Every day there are several news stories about cities across the country discussing the lead issue and how they meet the requirements of the Safe Drinking Water Act. While the average person may feel comforted by these news stories, it doesn’t mean that every home served by the water supply has lead below the EPA’s recommended action level. It’s the job of water treatment professionals to educate those served by municipal water about the regulations surrounding lead and copper and what those consumers can do to protect themselves further.
It is not uncommon to have a percent yield less than 100% as was observed in our experiment. Imperfect percent yield can be interpreted that the condition were not optimal and could be improved. Despite careful measurements some component will still be lost during transferring between containers. One way to get a better percent yield is by minimizing transfers. A low percent yield could be a result of evaporation
The decanted liquid had to be placed back into the freezer in order to refreeze the crystals to allow them to be decanted off. This could have caused a portion of the product to have been lost, thus affecting the percent yield and purity of the final product. Furthermore, there was an oiled substance thought to be a contaminant in the product after the addition of hot methanol and hot water to the Erlenmeyer flask. This contaminant was left in the Erlenmeyer flask to see whether or not it had an effect on the final product, but once the activated charcoal was added into the Erlenmeyer flask, the contaminant seemed to have latched onto the charcoal. Since it latched onto the charcoal and the charcoal was filtered out by way of gravity filtration, the contaminant is thought to have been filtered out as well. While the contaminant seemed to have been filtered out by the gravity filtration, there could be a small portion of the contaminant that remained in the filtered-out product, thus affecting the percent yield and purity of the final product as
Before the synthesis of the Copper Iodine Compound, the identities provided (CuNO3)2 and Nal weighed 1.65 g and 4.7 g, respectively. After being weighed, the (CuNO3)2 exhibited a blue color, while the Nal, through observation, was a white color. However, when both identities were combined, the product turned into a brown and red rocky material. Once 20 mL of deionized water was added, the product quickly turned pale pink paste. After the solution was repeatedly washed with a total of an additional 100 mL of deionized water, the product was powdery and pink with small grains, and was left to air-dry. Once the product was air dried, it was observed to be a pale pink color, while the filter paper was stiff as the product was hard and dry. Therefore, the solid was scraped off onto a recrystallizing dish. However, the mass of an empty recrystallizing dish needed to be recorded in order to compare how much of the synthesized copper iodide was obtained. Within this case, the empty recrystallizing dish used weighed 32.01 g, the product on the empty dish weighed 1.03 g, having a total weight of 33.04 g.
14 mL of 9 M H2SO4 was added to the separatory funnel and the mixture was shaken. The layers were given a small amount of time to separate. The remaining n-butyl alcohol was extracted by the H2SO4 solution therefore, there was only one organic top layer. The lower aqueous layer was drained and discarded. 14 mL of H2O was added to the separatory funnel. A stopper was placed on the separatory funnel and it was shaken while being vented occasionally. The layers separated and the lower layer which contained the n-butyl bromide was drained into a smaller beaker. The aqueous layer was then discarded after ensuring that the correct layer had been saved by completing the "water drop test" (adding a drop of water to the drained liquid and if the water dissolves, it confirms that it is an aqueous layer). The alkyl halide was then returned to the separatory funnel. 14 mL of saturated aqeous sodium bicarbonate was added a little at a time while the separatory funnel was being swirled. A stopper was placed on the funnel and it was shaken for 1 minute while being vented frequently to relieve any pressure that was being produced. The lower alkyl halide layer was drained into a dry Erlenmeyer flask and 1.0 g of anhydrous calcium chloride was added to dry the solution. A stopper was placed on the Erlenmeyer flask and the contents were swirled until the liquid was clear. For the distillation
Solid impurities and liquid impurities having quite different boiling points are most easily removed by distillation, but even liquids having similar boiling points can be separated. For easy separations, a "simple distillation" apparatus (Figure 1) will be used for the first part, but for more accurate separations, a "fractional distillation" apparatus (Figure 2) is necessary. In this lab we will be using both apparatuses. Unfortunately, each time a distillation is run, material is lost. Some evaporates into the air and some is left behind, stuck to the apparatus. That is why fractional distillation is the best apparatus to use. It is important to keep a careful record of the temperature at the beginning and end of every fraction you collect. Stop the distillation by removing the heat just before all the liquid in the distilling flask is completely gone. Watching the rate of temperature increase is important, allowing the temperature to increase too quickly can cause impurity. The distillation curves for our simple and fractional distillation clearly demonstrate that fractional distillation separates the two compounds more
In some instances lead reacted very similarly with the alkaline earth metal but very different in the other reactions such as with iodide. This is due to lead’s position on the periodic table as compared to those of the alkaline earth metals. The position on the periodic table correlates to an element’s atomic radius, ionization energy, and electron affinity. All of these properties affect an element’s chemical properties such as solubility. A systematic error occurred during my experiment when I observed a reaction between barium and iodide. There should have been no reaction. This error is probably the result of using a test tube that was not cleaned properly prior to combining Ba(NO3)2 with NaI. This experiment reinforced the concepts introduced in Chapter 8 of our textbook.
In Rosemary Jolly's class, students performed the hot plate procedure in order to evaporate the water from the unknown hydrate. The equipment that the students used were two 100-mL beakers, an analytical balance, a hot plate, and a clean glass rod to stir the substance. Students obtained about 1 or 2 g of the unknown hydrate into one of their 100-mL beakers. They determined the combined mass of the sample and the beaker. After doing this, they placed the beaker onto a hot plate that was on a medium setting. Using the glass rod, students stirred their beakers in order for all of the unknown hydrate to melt until a dry powder appeared. Once the dry powder appeared in the beakers, the students took their beakers off of the hot plate in order to cool to room temperature. They placed the beakers on an analytical balance to record the mass of the beaker and residue. This information was used later in the experiment to find the number of moles of water per formula weight unit of magnesium sulfate. Students repeated the procedure with their second 100-mL beaker. Once the second trial was completed, they used their data to determine the average number of moles of water present in the magnesium sulfate