Copper Coin Essay

To prepare the penny samples three pennies were obtained with one penny assigned to each group member. Each penny was weighed and their masses were recorded in the notebook. The year the pennies were made and the condition the pennies were in were also recorded in the notebook. In the fume hood each penny was placed into a 150 mL beaker. 25 mL of 6 M HNO3 was added to each beaker. The pennies dissolved and the remaining solutions were left to cool for 10 minutes. The three beakers’ contents were quantitatively transferred into three separate 100 mL volumetric flasks using a funnel. To make sure there was no loss of sample, the beaker was rinsed with 5-10 mL of water four times, each time the rinse solution being added to the volumetric flask. Still in the fume hood, 14 mL of concentrated ammonia solution was added to each volumetric flask using a graduated cylinder. The volumetric flasks were swirled to establish the blue color and dissolve any solids. If any

The hypothesis is rejected as the density of the pennies did not remain constant. The results show a 8% failure rate. This failure could be due to the makeup of the pennies. “In 1982, the mint introduced a penny that is 97.6% zinc and only 2.4% copper with a density of 7.2 g/mL. By comparison, the old pre-1982 copper pennies were 95% copper and 5% zinc with a density of 8.8 g/mL” (Bularzik, 2007). This is a 22% difference in density between the pre-1982 pennies and pennies made after that year. A source of error could be that pennies from this experiment were made during different years and therefore had different metal percentages.

In this experiment an elemental copper was cycled a series of five reactions where it ended with pure elemental copper as well, but at different stages of the cycle the copper was in different forms. In the first reaction, elemental copper was reacted with concentrated nitric acid where copper changed the form from solid to aqueous. Second reaction then converted the aqueous Cu2+ into the solid copper II hydroxide (Cu(OH)2) through reaction with sodium hydroxide. The third reaction takes advantage of the fact that Cu(OH)2 is thermally unstable. When heated, Cu(OH)2 decomposes (breaks down into smaller substances) into copper II oxide and water. When the solid CuO is reacted with sulfuric acid, the copper is returned to solution as an ion (Cu2+). The cycle of reactions is completed with the

The purpose of this lab was to make a substitutional alloy coating the penny in a gold color. The color of the penny depends on the Zinc and Sodium Hydroxide solution, and if heat was added or not. We took a copper penny and boiled it in a Zinc and Sodium Hydroxide solution. Then we took the penny out, rinsed it in water, and dried it off. Now the penny was silver. We then took the penny and waved it across a flame causing it to turn gold. Some errors that happened were getting Zinc in our water and over cooking the penny. These could be fixed by rinsing the Zinc off the penny in its solution before taking it out and not heating the penny for as long. A suggestion for improvement would be getting the flame at the lowest temperature possible.

Objectives: The lab experiment will consist of oxidation-reduction and double displacement reactions as well as titration techniques. All these components will be used in order to determine the percent composition of pennies. In conducting redox and double displacement we are able to analyze a penny and figure out the chemical composition of the product. The experiment entails careful observations and recording of evidence for a chemical reaction. In this experiment

Were your perceptions of the blue collar Americans transformed or reinforced by nickel and dimmed? Have your notions of poverty and prosperity changed since reading the book? What about your own treatments of waiters, maids, salespeople?

The first error that might have occurred was that the water and vinegar might have been covering the entire penny and the penny might not have been exposed to enough air. If the penny was not exposed to enough air, then the penny could have reacted differently toward the experiment. The paper towels were dry towards the end of the experiment and more water and vinegar was not added to the cups. This could have affected the way the penny was affected. With more water and vinegar, the pennies may have gotten more green or may have has a stronger reaction. At the end of the experiment, the pennies were taken out of the cups and placed a new paper towel. The towel was then labeled with sharpies and left to sit there for a day. The different chemicals in the sharpies could have affected the way the penny reacted. Since the sharpie marker was so close to the pennies, they could have easily been affected. Another experiment that people may want to do next is to the same experiment, but with different liquids. Instead of the vinegar being white vinegar, maybe one could try the experiment with a different type of vinegar, like apple cider vinegar. Apple cider vinegar has different ingredients and could be affected differently and have very different results. To conclude, there were many possible errors during this experiment and many scientific reasons on why the pennies reacted the way they

The purpose of this experiment was to find, compare, and contrast the mass, volume, and densities of copper and zinc pennies. Information about the pennies was acquired before the start of the lab. The pre-lab research stated that any pennies that were minted before 1982 are composed of pure copper, while any pennies after 1982 are made out of zinc. The densities of copper -- 8.96 grams per centimeters cubed -- and zinc -- 7.13 grams per centimeters cubed -- were also information that was acquired before starting the experiment. With knowing the density of the two metals, this hypothesis was formed: If the mass and volume of pennies made out of zinc and copper are both measured, then the copper pennies will have a greater mass, because copper has a greater density than zinc. This hypothesis was formed because density equals mass over volume and if the mass is greater in an object that has the same volume, then the density of the object will be greater than the other.

of the Indian textiles, that the flow of the silver bullion is very conflicted because

In this lab we will be heating up substances and use them to galvanize pennies. When you heat up the zinc, and then coat the penny in it, it then galvanizes the penny. Meaning, it helps protect the penny from oxygen and water. Afterwards, you will need to record data such as the mass of the penny. This helps keep track of what physical traits are being changed during this experiment. On part B of this experiment, you will be heating up the now galvanized pennies in order to see what reaction you get. The reaction you should receive from heating up the now zinc-covered pennies is that the pennies will change color.

In this lab, we will determine the percent composition of a modern (post-1982) penny by using a strong acid to react and dissolve the zinc core, leaving only the copper coating. Once only copper remains, we will compare its mass to the entire mass of the penny to determine how much of a penny is copper and how much is zinc.

When walking through the streets, have you noticed penny coins on the ground? If you did, did you wonder why? People today don’t find value in pennies, so when dropped, they don’t bother to pick them up. They degrade penny coins and want to eliminate the coins. Penny coins shouldn’t be eliminated because it has history and is valuable.

- Get out three cups, put water in the first one, soap water in the second one, and then vegetable oil in the third one. Take a dropper and get water in it, then add drop by drop onto a penny till it spills over the edge. Count how many drops there is on the penny while you drop them, do this for each liquid on a clean penny and clean dropper.

|1. Copper metal (penny) at the start |Tarnished, worn out, brownish, copper-colored, fine solid. |

When the zinc was added to the copper (II) sulfate solution, the solution started to bubble. As the solution was stirred, it turned a cloudy blue. Small flecks of a brown solid were visible. As the solution became colorless, the brown solid settled to the bottom of the beaker. The solid formed was copper in its elemental state. The color faded from the solution as the copper ions slowly formed into solid copper. The copper was poured into a funnel with filter paper and washed three times with 25 mL