Identification of Copper (II) Chloride Introduction Through a series of cation and anion confirmation and elimination tests, the identity of an unknown compound can be determined. By subjecting certain standards to a series of tests, it will be known how they react when trying to identify the unknown. The results of these tests are crucial to correct identification of the unknown compound. Materials and Methods 0.5 grams of the unknown 11 was added to 5 mL of distilled water in a centrifuge tube to make the stock solution. To determine the cation, 6 M NaOH was added dropwise to the unknown solution until a precipitate was formed.
Introduction The purpose of this lab is to determine the normality of an unknown base using a volumetric titration. The volumetric titration used for this experiment consisted of a standard acid called potassium hydrogen phthalate (KHC8H4O4) titrated with a weak unknown base. An acid-base indicator called phenolphthalein is used in order to view the reaction proceeding to completion. The indicator allows visualization of the acid changing colour when the solution has reached the end point. The normality of the unknown base is calculated after the solution has reached the end point.
How I did this was to note down the colour of the flame from each different metal salt solutions. Method: To do this experiment you will need a Bunsen burner, nichrome wire loop, hydrochloric acid 2M, salt solutions and water samples. First of you will need to clean your nichrome wire loop by dipping it into the beaker of hydrochloric acid 2M and then placing the wire into the flame until no colour is visible. Next you will need to get your 7 different metal salt solutions which are: Lithium, Sodium, Potassium, Copper, Calcium, Barium and Strontium, then one by one dip the nichrome wire loop into the hydrochloric acid and into your first metal salt solution which would be Lithium and then place the nichrome wire loop with the metal salt solution in the edge of the flame, Then finally when a colour shows in the flame note it down along with the name of the metal salt solution you are testing. Repeat this with the following metal salt solutions: Sodium, Potassium, Copper, Calcium, Barium and Strontium.
Fractions 1,2, and 3 were all separated by column/flash chromatography and their purities were measured with the TLC plate. One suggestion for future labs would be to use more accurate measuring tools. Post lab 1. So the solvent would not reflect the UV rays, therefore creating a dark spot on the luminescent TLC plate. This dark spot helps us measure how much the solvent moved on the TLC plate.
When I cleaned up I made sure I cleaned the surface area thoroughly and washed my hands. Conclusions and Observations: Table 1: Experiment Data | Grams | Percent of Mixture | Iron filings | 1.4g | 31.1 | Sand | 1.3g | 28.9 | Table Salt | 1.0g | 22.2 | Benzoic Acid | .8g | 17.8 | Total | 4.5g | 100 | A. My proposed procedure at the beginning of the experiment was a little different because I would have used the filter paper to get the sand out of the mixture. I did though propose to use the magnet to take out iron. B.
Then, by means of a dropper bottle and stirring rod, hydrochloric acid was added until all of the unknown carbonate appeared to have reacted. On a ring stand with a bunsen burner the HCl was evaporated, leaving only the NaCl. After cooling, the mass of the dish was taken once more. The mass of the left over NaCl was compared to the predicted yields to determine what the original carbonate was exactly. There was a high possibility for error in this experiment because the NaCl could not be heated a second time to make sure all of the HCl was evaporated.
The final crude product yield was 0.91g and the pure product yield was 0.36g. Error may have occurred during the extraction phase. Although I extracted twice with Sodium Chloride, if waste was not completely removed, it would affect the purity of the product. The distillation process may have also affected the pure product. The lab manual recommended that 0.5mL of waste be removed during distillation; otherwise it would affect the purity of the product.
We determined that the mass of zinc necessary to completely react with the copper (II) ions in the solution was 1.308g. We added an excess of 0.050 to make sure the copper completely reacted. 1.358g of zinc was then added to the solution. The solution with the zinc was heated and stirred until it was colorless, showing that the reaction was done. Hydrochloric acid was then added to the solution until the bubbles stopped in order to completely get rid of all of the zinc.
Observation 7 Hydrogen Gas was being performed. Observation 8 Zinc Chloride White bubbles started, and still has solid. Discussion: During the experiment we had to pour into the test tube 5 ML of Copper Sulfate Solution. Once this was done it started turning into a blue green color. Next, Zinc and Copper Sulfate combined which there was gas bubbles and the color changed into blue green color.
We used a calorimeter to monitor the light received by the photocell to determine the absorbance of different concentrations of cobalt chloride hexahydrate. Once we found the absorbance for each concentration we were able to calculate the concentration in moles of each solution. We were then given a solution of unknown concentration and by finding the absorbance of that solution we were able to compare the solution to the others and therefore find the concentration of the unknown. We were able to compare the unknown to the other solutions because there is a direct solution between absorbance and concentration for a solution, and this is known as Beer’s Law. Also the concentration of the unknown can be determined by observing the slope of the graph of Beer’s Law because the graph is linear.