Determination of percent copper in post 1982 pennies lab answers. What is the density of a post 1982 penny 2019-01-31
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What's a Penny Made Of?
The nickel also costs more than its face value to make about 8 cents , according to the report. So how did this happen? There could be minting errors, such as off-center, unfinished planchet, out-of-col … lar, brockage, stike-through, machine doubling, etc. The reaction between copper and nitric acid is an exothermic reaction. The function of using the ice bath in this step is to control the temperature of the reaction, because the reaction may become too violent if nothing is used to cool it down. Modern small cents were introduced in 1856. That made the metal composition of the cent 95 percent copper and 5 percent zinc.
The reaction takes place in an aqueous solution of a weighed sample of a copper-containing salt. Record the raw quantitative data in the table below: Electrical Potential Difference Between Zinc and Copper Solutions Electrical Potential Difference Variation in Copper Chloride Trial 1 Trial 2 Trial 3 0. In the early 80s the price of copper increased significantly and by mid-1982 the Mint was forced to strike cents out of zinc and copper-plate them so they looked like the older coins. If there was any solid zinc that did not react with the copper sulfate and was left over with the copper precipitate, zinc particles may have significantly changed the mass of the final product. Sources of Error According to the Law of Conservation of Mass, the mass of the products must equal the mass of the reactants, so logically one would expect that if 2 g of copper was used to start the lab, the lab would result in 2 g of copper. Purpose The purpose of this lab is to design a procedure to analyze the amount of copper in brass using. There were many possibly sources of error in the lab that could have been due to incorrect measurement from systemic or random error.
It also partakes in the regulation of the hearts rhythm. Determining The Percent Copper and Zinc in Pennies From Density Purpose: Practicing determine the density of the solution. Carefully place the pennies into the graduated cylinder, record the final volume of the water in data table. Using the linear relationship to determine the percent of density by the solution. From 1942 till that year the Canadian cent was 98% copper. Creative Commons License Meaning: so long as you credit my work to me, you're free to share, copy, modify, or sell my work. Magnesium completely displaces copper from the solution allowing for measurements.
The reaction that occurred in step 7 was a dehydration reaction. Carefully place the pennies into the graduated cylinder, record the final volume of the water in data table. Anyway, t … he price of zinc has gone up too so now there is about 1. The penny is composed of 2% copper and 98% zinc. The faces on all coins currently in circulation face left, except for on the penny.
The Related Links show the prices of Lincoln and Indian Head cents so you can see just how broad a variation in prices there is! Fill a 100mL graduated cylinder to 40mL or enough to fully submerge the pennies with water, record the volume in data table. Find the best-fit straight line. For example, financial companies Company Q is a small local grocery store chain located in a major metropolitan area. With the understanding of these concepts we can calculate or hypothesize for the properties of each element or compound. Well the answer I'm getting can't be right because it is more than 100%. Therefore, the purpose is to determine the density, solubility, recrystallization, extraction, separation, and drying of products by using small quantities. Determining the volume of the different percentages of zinc and copper mixtures.
This was performed due to the change in the amount of copper used for pennies after 1982. Repeat steps 13-18 for all variations of Copper Chloride. Repeat this procedure twice more. There are many years that have valuable 1 cent coins. The flasks were removed from the heat and 6M ammonia solution was added until the copper hydroxide precipitate appeared.
The analysis of copper percentage of both pre and post 1982 pennies was analyzed using iodometric titration and the results of all students was compared. Mass 20 pennies, record data. Using that fact you can estimate the density. So they decided to use zinc, with is stro … ng and also cheaper. Put the pennies 5, 10, 20, 30 into the mixtures; determine the volume of the pennies.
It would cost more to … recover the few milligrams of gold plating than you could make by selling the metal. All in all, there was an abundance of sources of error in this lab. Wash the penny with soap and water to get it clean. The solution was further titrated until the solution became a dark gray purple. For this I shall be using full fat milk and semi skimmed milk, to discover which, if either have a higher content of calcium. As the years passed, the percent composition of copper in the penny decreased.
