The experiment was to investigate what are the products of a chemical reaction, more specifically, what iron compound is formed. A chemical reaction is anything that has had a color change, the formation of a solid, bubble, or a temperature change. In an oxidation-reduction reaction, charges of molecules are going to change. The first balanced equation was Cu〖SO〗_4+Fe(s)→Fe〖SO〗_4+Cu. The second balanced equation was 2Cu〖SO〗_4+3Fe(s) →3〖Fe〗_2 (〖SO〗_4 )_3+Cu. Given the two different chemical formulas, the theoretical yield was found to determine how much copper would be left over after the reaction by using the balanced chemical equations and stoichiometry. With the iron being the limiting reagent, we knew that the excess of copper product …show more content…
After figuring out the mass of the empty beaker to be 72.5 grams, 100 milliliters of water were heated using a hot plate. The water warmed just below boiling. Once the beaker of water was removed from the hot plate, 12.1 grams of copper (II) sulfate was added. Once the copper (II) sulfate was stirred, 1.5 grams of iron filling was added to the beaker and set to allow the copper to settle on the bottom of the beaker. Once the beaker was cool enough to touch and the copper was settled to the bottom, we began the decanting process. Decanting was used to remove the limiting reagent, the iron sulfate compound, to dry out the excess reagent, the copper. The copper was decanted twice again with water to clean off any left over iron sulfate compound. Then the copper was covered with acetone and put in an oven for 15 minutes to dry completely. Once the copper was dried, the electronic balance was used again to measure the mass of the beaker and the copper. Once this mass was calculated to be 75.2 grams, the empty beaker’s mass of 72.5 grams was subtracted from it to give us the total mass of the copper, which was 2.68 grams. We knew a reaction occurred when a solid formed at the bottom of the …show more content…
This answer of 104% is our percent yield. With our percent yield being over 100%, human errors obviously occurred. The mass of the beaker could be off or if more than 1.5 grams of the iron filling was added, this can answer the reasoning for having more than 100% percent yield. Our group still managed to say that the product formed was iron (III) sulfate. When comparing data with other groups, there was a vast range of percent yields in the lab. Possible error with decanting or not allowing the copper to completely dry could have answered the fluctuation in numbers. Our group was the only one a percent yield of over 100% but still had the correct iron filling. When checking over the calculations, the class agreed that the product produced was iron (III) sulfate. After checking our calculations again, there is no answer for how our group had over 100% percent yield, even with decanting. Usually during decanting, it is usually not as
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
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)?
One of the best methods for determining mass in chemistry is gravimetric analysis (Lab Handout). It is essentially using the the mass of the product to figure out the original mass that we are looking for. Thus the purpose of our experiment was to compare the final mass in our reaction to the initial mass and determine the change in mass.
The percent error or percent yield between the theoretical yield of Cu produced and experimental value of Cu produced was approximately 107 %. One source of error, which was a scientific error, was that leaving the Cu precipitate in the cupboard for week allows dust to accumulate on the sample. When dust accumulates on the Cu precipitate for a period of one week, it adds additional mass when weighed. This is because dust has mass, and as more and more dust accumulate, the accumulation of dust will have a greater mass. As a result, the experimental mass of Cu produced would be greater than the theoretical value of Cu produced in the reaction since the precipitate weighed on the electronic balance is also considering the mass of
Discussion: The percent of errors is 59.62%. Several errors could have happened during the experiment. Weak techniques may occur.
A test tube containing 0.2 gram of manganese dioxide was weighed. After recording the data, 1 gram of the unknown substance was then added into the test tube and weighed again, the data recorded also. The test tube was heated using a gas burner and was held by the clamps of the iron stand. The heating continued until there was no more gas rising out of the mouth of the tube which signified that the chemical reaction had already ceased. The test tube was set aside, allowing it to cool to room temperature. When it had reached room temperature, it was weighed and the data recorded. After recording the weight of the test tube and its contents after heating, a second test tube was also weighed with 0.2 gram of manganese dioxide in it. The data was then recorded. A second unknown which is a mixture of potassium chlorate and potassium chloride weighing 2 grams was then placed on the test tube, it was weighed and the data recorded as well. It was held by the clamps on the iron stand and heated using the gas burner. Similar with the first part of the experiment, it was heated until there was no more gas ascending out of the test tube. It was allowed to reach room temperature. The test tube was the weighed and data recorded.
Refer to Chemistry Lab # 2 – Investigating Changes. No changes have been made in this experiment. Methods = == ==
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
The purpose of performing this lab was to find the specific heat capacity of an unknown metal.
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
of Copper Sulphate. To do this I plan to work out the amount of water
First, put on safety goggles to protect the eyes from the chemicals used in this experiment. To begin the lab, label one 100-mL beaker “HCl” using a beaker marker and add 30 mL of 1.0 M Hydrochloric acid solution to this beaker. Next, label the other 100-mL beaker “Na2S2O3” and pour 30 mL of 0.30 M Sodium thiosulfate solution. Finally, label the 250-mL beaker “H2O” and add 25 mL of Distilled or deionized water into this beaker. After all the beakers have been labeled and filled with their set solutions, place a sheet of white paper underneath the six-well reaction plate and using the black sharpie, draw a “X” under each of the wells. Before beginning the lab, place the six-well reaction plate over the sheet and verify that the six “X’s” can be seen through the plate.
borate) and 1.0 g. of sodium hydroxide in 20 mL of warm water. It may
Determination of thermodynamic values allows for analysis of what makes a reaction spontaneous. In this experiment, the equilibrium constant of the crystallization of potassium nitrate as it ionized in water was found and used to determine enthalpy, entropy, and Gibb’s Free Energy of a reaction. The variables were found by by graphing the solubility of potassium nitrate as a function of time and by utilizing relationships based on the van’t Hoff equation. Based on the determined Ksp of 43.4 the average Gibb’s Free Energy over on six trials was -8.4834 kJ/mol with a 510 % error. Relations based on the graph of ln(k) vs. 1/T(K) showed the enthalpy of the reaction to be +34.78 kJ/mol yielding a 2.30% error, and showed the entropy to be +137.4