Abstract
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
Introduction
Aluminum is the third most abundant element and most abundant metal in the Earth’s crust. Aluminum is never found in the free element state in nature. It
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normally exists as a bauxite, an aluminum ore with the formula Al2O33H2O. (Synthesis of Alum crystals Lab) Because of aluminums low density, high tensile strength and resistance to corrosion it is widely used for the manufacturing of automobile products aluminum cans and aluminum foil. Recycling aluminum has become a positive attribution to saving our environment and most recycled aluminum is melted and recast into other aluminum metal products or used in the production of various aluminum compounds like alums the form of dry crystals. (Synthesis of alum) Experiment Materials used in this lab include 250mL beaker, 400mL beaker, and short stem funnel, filter paper, stirring rod, 250mL Erlenmeyer flask, Buchner funnel, hose, ring stand and a ring stand clamp. 1.
Al to Al(OH)4 – (aq). Cut and Measure approximately one gram of aluminum off the side of a soda can. Take a piece of stainless steel scouring pad to remove the coating from both sides of the aluminum. Cut the Aluminum into smaller pieces to increase the surface area so the rate of the chemical reaction can increase and dissolve more quickly. Reweigh the aluminum to determine its exact mass. In a hood, add the aluminum to a 400mL beaker containing 50mLs of KOH potassium hydroxide. Allow the solution to sit until all of the aluminum has dissolved. This process could take up to 20 minutes. You may also need to use a low heat setting on a hot plate. During the reaction, the product will turn a dark grey color. The reaction is complete once all of the aluminum has dissolved and hydrogen gas ceases to evolve. After the aluminum has dissolved use gravity filtration to remove all solids from the solution, collect the solution into a 250 mL Erlenmeyer …show more content…
flask. 2. Neutralization of excess KOH (aq). Slowly add 25 mLs of 9 M H2SO4 (Sulfuric acid) to the filtered solution while stirring. There should be a white aluminum hydroxide precipitation forming. As you add more sulfuric acid you should see heat evolving and the precipitation dissolving. Continue to heat the solution while stirring to dissolve all of the precipitation. Remove the solution from the hot plate and allow it to cool. 3. Crystallization of KAI (SO4)2*12H2O (s). In the meantime, prepare an ice bath by filling a 400 mL beaker half – full with ice and cover the ice with water. Sit the 250 mL beaker containing the product inside the ice bath to cool. Let it sit in the ice bath for about 15-20 minutes until most alum have predicated from solutions and crystals have formed. 4. Vacuum Filtration. While the mixture is cooling put together the filtration apparatus with a Buchner funnel for vacuum filtration. Use a filtration paper that fits the funnel covering all of the wholes to ensure all crystals formed are collected. Lastly, mix 10 mL of ethanol and 5 mL of distilled water and let crystals chill on ice bath for a few minutes. Using a dropper rinse the remaining crystals from the beaker into the funnel and rinse the collected crystal with the ethanol and water mixture. Continue to allow the vacuum to pull liquid until product is completely dry. Allow the crystals to air dry and collect the on a pre weighed watched glass. Take the mass of the alum and watch glass once the product is completely dry. Results and Discussion The results on the production of synthesize of alum indicated the mass of the starting Aluminum from the soda can was 1.0528g. While the mass of the crystals formed was 14.3123g. The mass of the watch glass was subtracted from the mass weighed from the crystal and watch glass together and determined to be 14.3123g of Alum. The calculated moles of product (KAI (SO4)2)* 12H2O was determined to be 0.390215 moles. The percent yield was calculated from the results and determined to be 1,423%, which is relatively high but was expected because the product contained impurities. A product that contains impurities causes the mass to be larger than it actually would be if the product was pure. The data collected have very little precision, which there is a likely source of error. Errors could have occurred by losing some of the alum either while transferring the product from one beaker to another beaker, or by splattering the product while heating the solution. Those errors could make the mass smaller as well as the moles of the product smaller than it actually would have been if all the product was collected properly. There could be some modifications used to prevent an error from occurring such as, carefully collecting all crystal pieces from filter and being careful not to spill the product. Conclusion In conclusion, pieces of aluminum from a soda can were synthesized into aluminum potassium sulfate also known as alum.
The experiment was not a success, there was percent yield of 1,423%. With a percent yield that is relatively high at 1,423% did not conclude a successful experiment, because impurities added to the mass of the actual product. There were many errors in this lab due to the product being transferred on numerous occasions as well, as spillage and splattering of the solution. Overall, learning how to take one product and chemically create something else as well as how working with others effectively turned out to be a
success.
The experiment was successful in terms of receiving alkenes by dehydration in the product and not water as seen from the IR
Anne Zhang 3/6/14 BSGE 7-1 Lab Report Problem Paragraph 1 Question: What is the effect of temperature on the dissolving time of an Alka-Seltzer? Alka-Seltzer is made up of baking soda, aspirin, and citric acid which gives the tablet the fizz when dropped in any temperature water. “Alka-Seltzer is a medication that works as a pain reliever and an antacid.
2-ethyl-1,3-hexanediol. The molecular weight of this compound is 146.2g/mol. It is converted into 2-ethyl-1-hydroxyhexan-3-one. This compounds molecular weight is 144.2g/mol. This gives a theoretical yield of .63 grams. My actual yield was .42 grams. Therefore, my percent yield was 67%. This was one of my highest yields yet. I felt that this was a good yield because part of this experiment is an equilibrium reaction. Hypochlorite must be used in excess to push the reaction to the right. Also, there were better ways to do this experiment where higher yields could have been produced. For example PCC could have been used. However, because of its toxic properties, its use is restricted. The purpose of this experiment was to determine which of the 3 compounds was formed from the starting material. The third compound was the oxidation of both alcohols. This could not have been my product because of the results of my IR. I had a broad large absorption is the range of 3200 to 3500 wavenumbers. This indicates the presence of an alcohol. If my compound had been fully oxidized then there would be no such alcohol present. Also, because of my IR, I know that my compound was one of the other 2 compounds because of the strong sharp absorption at 1705 wavenumbers. This indicates the presence of a carbonyl. Also, my 2,4-DNP test was positive. Therefore I had to prove which of the two compounds my final product was. The first was the oxidation of the primary alcohol, forming an aldehyde and a secondary alcohol. This could not have been my product because the Tollen’s test. My test was negative indicating no such aldehyde. Also, the textbook states that aldehydes show 2 characteristic absorption’s in the range of 2720-2820 wavenumbers. No such absorption’s were present in my sample. Therefore my final product was the oxidation of the secondary alcohol. My final product had a primary alcohol and a secondary ketone
The question that was proposed for investigation was: Can the theoretical, actual, and percent yields be determined accurately (Lab Guide pg. 83)?
I did accomplish the purpose of the lab. First, I determined the percentage of water in alum hydrate, and the percentage of water in an unknown hydrate. The results are reasonable because they are close to the example results. Second, I calculated the water of crystallization of an unknown hydrate. Furthermore, I developed the laboratory skills for analyzing a hydrate.
The sand is If the water with Alka-Seltzer tablets is stirred during the reaction, then the rates of reactions will increase because the particles will be forced to make contact with each other and... ... middle of paper ... ...results anomalies because they are the outcome of dissociation of calcium and magnesium ions,. Evaluation: What is the difference between My results were very reliable, because by looking at my graphs I can see a trend that relates to my scientific background. It is also evident that I have obtained a reliable set of results when I see that.
Objective The ability to analyze a substance and determine properties of the substance is an important skill for AP Chemistry students. Major concepts for the “Analysis of Alum” laboratory are percent composition, water of hydration, and molecular formula. They will be used in three different experiments to determine the melting point of alum, the mole ratio of hydrated water to anhydrous alum, and percent of sulfate ion contained in alum. The values acquired in the lab should be close to the calculated values of 92.5 ˚F, 12 moles of water to 1 mole of alum, and 59%, respectively.
... got very different results, however they had carried out the experiment in slightly different ways, making it difficult to compare results.
Calcium is the 20th element of the periodic table. It is a metallic element that is greyish-silver in colour and has the atomic symbol of Ca. It is a group 2 alkaline earth metal and is the 5th most abundant element by mass in earth’s crust. It is also reactive with water and is relatively soft. It is an essential element for organisms, and is major material that is used in the materialisation of teeth, bone and shells. It is also the most abundant metal located within animals.
== Refer to, Chemistry Lab #1 – What’s the substance? However, I changed some of procedures during my experiment, here is the changes I made in this experiment: * I only used the toothpick to place a small amount of each sample on a separate piece of paper, instead of the spatula.
The conical vial was placed in a small beaker and allowed to cool to room temperature. The mixture was Cooled thoroughly in an ice bath for 15-20 minutes and crystals collected by vacuum filtration on a Hirsch funnel. The vial was rinsed with about 5 mL of ice water and transferred into to the Hirsch funnel and again washed with two additional 5mL portions of ice water. Crystals were dried for 5-10 minutes by allowing air to be drawn through them while they remained on the Hirsch funnel. The product was transferred to a watch glass plate and allow the crystals to dry in air. Crude acetaminophen product was weighed and set aside a small sample for a melting point determination and a color comparison after the next step. Calculation of the percentage yield of crude acetaminophen (MW = 151.2). was done and recorded in the lab notebook.
In a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved.
Aluminum is number thirteen on the periodic table and it’s atomic weight is twenty seven. The melting point of aluminum is 660.2 degrees Celsius. The density of Aluminum is 2.7 grams per cubic centimeter. In nature, aluminum cannot be found uncombined.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.