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.
Once the material was acquired, 1.0094 grams of Aluminum were weighed and then transferred to a 250mL beaker. The 250mL beaker continued to remain in use for the next few steps. 1.4M KOH solution was added to the Aluminum sample that was previously obtained. For gas to escape the lab, there was a fume
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.
After identifying the first cation, the following procedures identified the second cation, which was barium or calcium. The second cation was identified by using the liquid portion of the solution mixed with hydrochloric acid and separated from the white precipitate, silver chloride after being centrifuged. Ammonium carbonated, which serves as to help confirm the presence of either barium or calcium cation, was added and stirred to this existing solution, causing the solution to become cloudy and white. Afterwards, the solution was heated and occasionally stirred in a hot water bath, the white precipitate began settling at the bottom of the test tube, which could be either barium carbonate or calcium carbonate. Once the test tube was left to cooldown, it was
The objective of this lab is to see the effect of hot and cold rolling of Al 5083. And to see the effect of cooling on a casted Aluminum 7075 alloy. Once the alloy is cast it will be cold rolled to 20, 40, 60, and 80% reduction and hot rolled to 40, 60, and 80% reduction samples. The rolling will produce a change in the hardness and grain size. The hardness will be tested using a Rockwell hardness test for the grain size measurements we will etch and anodize the surface.
Major unknown #202 was given out by the instructor, and the unknown bacterium was streaked out on a Trypticase Soy Agar tube and plate to inoculating the bacterium and incubating. After incubated and grown the morphology was observed and several Gram stains were performed to determinate if the bacterium were gram positive or negative, and the morphology of the bacterium. The Gram Stain of my major unknown #202 was determinate to be Gram negative bacilli, and was double checked by the Gram check slide. Also I noticed that my bacterium was a facultative anaerobe and according to my results of endospore test, my bacterium has not endospores. So according to the list of possible major unknowns provided by the instructor, I narrow my bacterium thru
Since the crude solid’s melting point range coincided with the purified melting point range of the purified solid, the recrystallization process indicates that the compound of interest was the same, only more refined. Both ranges were small, with the recrystallized melting point values being more precise, therefore indicating that the purity was evident. Meanwhile, the distillation for the liquid resulted in two different refractive indexes which varied significantly from each other. While this could be apprehended as a sign of impurity, the large difference between the two refractive indexes of 0.1769 indicates that the distillation process did not produce a very pure liquid from the start. The temperature could have a role in this large difference between the crude and the purified liquid sample as the refractive index can change with temperature 2.
After being dissolved in a minimal amount of hot 95% ethanol, crystal formation began again once water was added until the solution looked semi-opaque. After cooling, the flask was placed into an ice bath for
The purpose of this experiment is to prove that the amount of crystallization will be greater when some crystals are already present. To conduct the experiment, 6 jars were prepared. Four cups of sugar and two cups of water were combined in a pot and boiled on the stove until a temperature of 215 degrees. After removing from heat, an additional 12 tablespoons of sugar were added to the solution as it cooled. Equal amounts of the cooled solution were poured into jars.
Alkaline Earth Metals Lab Report INTRODUCTION: This lab is designed to find a pattern in reactivity of different alkaline earth metals. Alkaline earth metals are elements in group 2 of the Periodic Table of Elements. These include Calcium, Magnesium, Barium, Strontium, Beryllium, and Radium, all of which are found in natural compounds and react with water, except for beryllium. Groups are sometimes called families, because they share chemical properties, behaviors, and reactions, due to the fact that they have the same valence electron shell configuration.
Elements react to the different solution in different ways. Some show a chemical or physical reaction and some don’t show any kind of reaction. By using four elements and four solutions we are trying to see which out of all of these elements is the most reactive. We are trying to determine which element would be the most reactive? The elements are copper, zinc, silver, and magnesium.
The amount of water collected through the distillation process was small as there was too much seawater used and therefore it was unable to fully evaporate. If the water had been evaporated the results would have been clearer that the water was pure. In the second part of the experiment the water was tested before hand to ensure that the water was seawater using silver nitrate and then later tested to find out what ionic compound it had in it, sodium chloride. Glass bead were placed into the pear-shaped flask to control the boiling water.
The lab was performed using the thermometer, the graduated cylinder, the scale, the pipet, and many more lab equipment. There were four separate parts. The first part of the experiment consists of examining the meter stick, and using the meter stick to measure the length and width of the lab notebook. The second part of the experiment consists of observing the graduated cylinder. You had to fill it with water and estimate the closest value to the measurement on the side of the graduated cylinder.
Introduction and Historic Background Sodium chloride is also known as salt. The molecular formula for sodium chloride is NaCl. NaCl has a molar mass of 58.443 grams. Sir Humphry Davy discovered sodium chloride in 1807. He was able to extract sodium from its compounds, which included sodium’s connection with chlorine.
One is that the base was not exactly the right Molar solution wanted but was only off by roughly 0.001. In this experiment there were a few risks in doing it so certain measures were taken to make sure nothing happened. As the experiment was dealing with an acid, lab coats and goggles were warn. Also as there was the chance of broken glass, when using any glassware it was to be handled with care.
