Penny Lab

In the experiment, What Goes Around Comes Around, the element copper was put through a series of chemical changes to observe whether or not the final copper precipitate had the same mass as the initial mass of the copper. The purpose of this lab is to prove the Law of Conservation of Mass, which states that mass cannot be created nor destroyed. In the experiment, if the final mass of the copper precipitate is equal to the initial mass of copper, this law is proven because the copper was not destroyed in the chemical reactions nor was it created. Copper was first combined with the compounds nitric acid(HNO3), water(H2O), and sodium hydroxide(NaOH). This mixture was first chemically separated using heat to boil out the water. The aqueous solution

The main goal of this experiment was to observe series of reactions that convert a piece of copper metal, via several different copper-containing compounds, back into its original elemental form. The data collected was the striking color changes along with their relevant chemical equations. The data was collected while keeping a close eye on the experiment the whole time. The data recorded was used to see the different changes involved with a piece of copper metal. The copper was weighed and heated multiple times throughout the experiment

Washing of the copper is necessary in this experiment to separate the iron from the copper and make sure the iron is not counted in the mass of the copper.

Introduction: The purpose of this lab was to learn the proper techniques of roasting, smelting, and volumetric analysis to determine an unknown sample of copper mineral.

Also the top pan balance should be carefully wiped between readings to ensure that copper sulphate solution, water or any other substance is not left on the balance from previous readings as this will affect the reading.

The metals used in producing the penny are too dangerous and costly. First, zinc and copper are the main components in the penny production, which is threatening to the environment. First, almost all the penny is made up of zinc, which in high doses is harmful to animals and even humans. According to “Livingston”, “In addition, zinc itself, though in small amounts, is harmful in high doses to both humans and animals.” Second, zinc and copper are too expensive in the making of the penny. To justify, the demand price for zinc has doubled and the demand price for copper has tripled. As mentioned by “Browning”, “Worldwide demand for copper, nickel, and zinc have

XIV. Record your observations of the dried, cooled copper metal and weigh the recovered copper.

Although through the centrifusion and spot test at step 2 it was determined that the sample contained Silver and Lead. The same methods were used as in Part III to attain these

11. Recorded volume of water displaced in the 100 (+/- ?) mL graduated cylinder #1 and other necessary quantitative and qualitative observations of the process and the products of the reaction. Then, washed out the Erlenmeyer flask for 5 seconds and used the test tube brush to clean out any leftover solution. Afterwards, allowed the Erlenmeyer flask to air dry and used the second Erlenmeyer flask to perform trial 2.

At 60 minutes the pectin powder was able to further reduce the copper concentration by only 53 milligrams, giving us a final copper concentration of 299 milligrams from the original 500 milligrams of contamination. After 90 minutes, the copper

During lab, we put the metal copper under different circumstances so that we could gain a better understanding as to what goes on in the copper cycle. Throughout each stage of the copper cycle, we deduced what type of chemical reaction took place based on observation, made observations about the state of the metal and what type of environment it was subjected to, and determined what the net ionic equation was for each stage. Following the experiment, we calculated what the percent yield was and compared the changes in mass from the initial stage to the final stage.

The density of object C still had a 11.6% error if it was copper, but this was the lowest percent error if object C’s density is compared to the densities of all of the known densities, meaning the density of object C is most similar to that of copper. Not only did the density point to this object being copper, but the bronze color possessed by object C was similar to the bronzey copper color of copper substances alluded to them being the same substance. Using the evidence provided by both the densities and colors of these substances, we identified object C as being copper. We used the same procedure in order to

Assuming the calibration curve for the copper ions is accurate, there is a linear relationship between the molarity of copper and absorbance, with a slope of about 3.3005. Using this constant and knowing the amount of light absorbed by the sample of brass shots (0.526), one can calculate the molarity of copper, which is about 0.159 M in this sample. Using this and the volume of the sample given, which is 0.1 liters, the moles of copper can be calculated and then multiplied by the molar mass to yield the grams of copper in the brass shot, which is 1.01 g approximately. Finally, dividing the grams of copper by the total mass of the brass yields the percent composition of copper in the brass shot, which in this experiment was about

The first source of error that could have occurred in this experiment relates to the decanting process for which we were starting to separate the newly produced copper from the solution. Even when carefully pouring the mixture of deionized water and the solution into the sink, loose copper particles, most invisible to the naked eye, would have escaped from the beaker. This would lessen the overall mass of the copper from what it should be as not all of the weight of what was produced would be accounted for. For the relative masses of copper and iron, the reduced mass of copper would make the final calculated experimental ratio of masses lower than in actuality because the proportion of copper to iron would have a decreased range.

The objectives of the experiment are to use the analytical balance correctly, to gain an understanding of some concepts of statistical chemistry, and to apply statistical concepts in analytical chemistry. The experiment preceded by ten teams weighing ten 25-centavo coins using an analytical balance, weighing by difference. After doing the calculations to analyze the data, some of the values were rejected from their data sets.