The percent recovery of the copper was calculated using the equation, percent recovery = (the mass of the copper recovered after all the chemical reactions/the initial mass of the copper) x 100. The amount of copper that was recovered was 0.32 grams and the initial mass of the copper was 0.46 grams. Using the equation, (0.32 grams/0.46 grams) x 100 equaled 69.56%. The amount of copper recovered was slightly over two-thirds of the initial amount. Throughout the experiment, copper was altered a total of 5 times, but after the final chemical reaction, solid, elemental copper returned. Each time the solution changed color, a precipitate formed, or when gas appeared, indicated that a chemical reaction was occurring. For the first reaction, copper was added to nitric acid, forming the aqueous copper (II) nitrate (where the copper went), along with liquid water, and …show more content…
There are only two circumstances in which I think the copper could have been lost. The first chance where some of the lost mass of copper may have gone could have been during the first reaction. If distilled water was added to the solution before the chemical reaction finished, some copper may have been lost during that step. While all nitrogen dioxide gas seemed to have dissipated, perhaps, it was not finished yet. By stopping the reaction early, all of the solid, elemental copper may have not had a chance to react with the nitric acid, and some mass may have been lost during the step. The other time where mass could have been lost was during reaction 3, more specifically each time the liquid was decanted. Although a few black sand-coffee grains of the copper (II) oxide lost do not seem like a significant amount, they do have an impact on the final result, and each time a few of the grains were accidentally decanted could have an impact on why our final recovered mass was less than the initial amount that we began
To calculate the percentage of Cu, we divided the final mass of the penny 0.09 and the initial mass of 2.47 and multiplied by 100. To calculate the percentage of Zn, we divided the final mass of the penny 2.38 and the initial mass of 2.47 and multiplied by 100. During the experiment the hydrochloric acid donated its hydrogen ions in the reaction and then the chloride ions reacted with the zinc ions in the solution. Thus, the zinc dissolved in the highly acidic solution which was caused by the high concentration of H2 ions. Hydrogen gas was generated during the reaction which was seen when bubbles were formed as the penny was dissolved into the beaker.
Discussion 1. Zn0 (s)+ Cu2+S6+O42-(aq) →Cu0(s) + Zn2+S6+O42-(aq) Zn0(s) → Zn2+(aq) + 2e- Cu2+(aq) + 2e- → Cu0(s) Zn0(s) + Cu2+(aq) → Zn2+(aq) + Cu0(s) Oxidant (oxidizing agent) is the element which reduces in experiment.
Then the mass of the copper metal and the percentage of Cu were obtained and compared throughout different groups and a mean and standard deviation was calculated for the
After I rinsed the copper I transferred it to a watch glass that had been baked for 20 minutes so it would not contain any liquid so as to not counteract the experiment. After I put the copper on this watch glass I baked the copper in the oven for 20 minutes so there would be no liquid left in that to mess up the mass. After 20 minutes I removed the watch glass with the copper in it and weighed itm making sure to weigh the watch glass
Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.
To better understand this law, Cu(s) was transformed with different reactions only to return back to Cu s). The initial and final mass of Cu(s) was recorded to give the percent recovery of copper product at
Error Analysis We may have made a few errors along the way. We could have had a blunder because we may not have waited long enough for the penny to stay on the scale. We could have made a human error because we could have had a little more or less sodium hydroxide in our graduated cylinder and eyeballed it wrong. Another error you could have made was an instrumental limitations because read the cylinder wrong on the side by
This experiment is performed to test how Daphnia react when exposed to differing levels of copper sulfate so that we may understand what effects it has on underwater organisms. One possible hypothesis is, if the levels of copper sulfate in their environment rise, more of the Daphnia will die because copper sulfate is toxic. Daphnia are members of a collection of small crustaceans that are commonly called water fleas that are commonly found in small lakes and ponds. They reproduce through parthenogenesis, only creating male eggs once food becomes scarce. They eat algae, bacteria, and yeast.
The purpose of this lab was to change pennies from copper to silver to gold, like alchemists have attempted to do in history. Through the data and observations gathered throughout this experiment, it can be concluded that the pennies were not changed into a different element. For example, the density of the penny from 2005; which was the penny that was experimented on to see whether or not it could turn into silver; was 4.62 g/cm3 before the experiment and 4.89 g/cm3 by the end of the experiment. If this copper penny really would have turned into silver, then the density of the penny would be 10.49 g/cm3; which is the density of silver; by the end of the experiment. The penny may have turned silver in color, but this was only because it was plated in the zinc that was added to the beaker of water in the experiment.
RESULTS AND DISCUSSION Table of Results DDA Concentration (M) Initial Mass(g) Time Interval Recovered Mass (g) Cumulative Mass (g ) Cumulative Recovery (%) 10^(-5) 160 0
The volume stayed consistent because to decrease, the process needs activation energy. Once the activation energy was stored, the compost started to decrease almost linearly. The decreasing was due to worms eating the compost and disposing some of it as dirt, disposing some into the air (CO2), and using other part of the compost like the H’s as energy. This was due to cellular respiration; the worms used the compost for glucose, and due to homeostasis unused molecules were released through respiration.. The compost stayed constant again at the end of the experiment because worms started to die, and weren’t able reduce any more
Copper Cycle Lab Report Ameerah Alajmi Abstract: A specific amount of Copper will undergo several chemical reactions and then recovered as a solid copper. A and percent recovery will be calculated and sources of loss or gain will be determined. The percent recovery for this experiment was 20.46%.
Using the Law of Definite Proportions, the mass of this product was used to determine the number of moles of copper and chlorine in the sample, which led to being able to determine the
If only one reactant is increased, then the chemical reaction will only produce a certain amount of products after the limiting reagent is used up, and in this experiment, the most mass the reaction could produce was 0.4 grams. Although we kept adding calcium chloride, not adding sodium hydroxide in the same proportions will not yield more product, which is the main goal in conducting this lab. We should have seen a plateau at 0.4 grams to show that the limiting reagent inhibited further Ca(OH)2 production, but we made several mistakes in our experiment, which made the data unusable to conclude. Once again, the data is polluted, so these number are not accurate, but it is the data our group has to work with. The theoretical yield should have been more than the actual yield, and the percentages should have been less than 100.
But the difference was no bigger than 0.08, and after the values were rounded the same empirical formula was deduced. So the experiment can be concluded as successful. Evaluation: The method used was simple and easy to follow; however, it did not include how much oxygen was needed to react completely. Also it didn 't mention what magnesium oxide looked like after it finished reacting, so it was a guesswork of determining whether the reaction was finished or not.