Turning Copper Into Gold Experiment

The pennies used in this experiment were created in 1990, 1993, and 1995. The pennies were all created after 1982 when the percentage of copper authorized by Congress in a penny was changed to 2.5% by mass. This fact led to the hypothesis that because all three of the pennies were created post-1982, their mass will be approximately 2.5% copper. However, facts that must also be be taken into consideration are the age of the penny and the condition it is in because the copper is on the outside of the penny and is susceptible to wear and tear.

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.

For our science assessment we had the task to research about a metal of our choice. Since I am really into computers, I chose copper. A metal used in all kinds of wires, cpu’s and other stuff without a computer wouldn’t work. This fits really well into what we have to do for the second part, describe how this metal has helped human society.

Obtain a 50 mL beaker for the experiment. In the first part of the experiment, you dissolve the zinc core of a penny and leave the copper covering intact by putting four notches in

The Cu Later lab experiment is designed to allow you to practice lab skills in implementing and performing a series of reactions. Specifically, four types of chemical reactions will occur: oxidation/reduction; double replacement; single replacement; and decomposition. You will begin with a known amount of copper metal, which, after progressing through several steps, is reproduced. In this experiment you will observe and record the various changes such as heat, color changes, and production that occur. This procedure is used to observe some chemical reactions of copper and its compounds while also performing the lab appropriately as to retain the copper as much as

The purpose of the lab copper- silver nitrate reaction is to find the mole relationships between reactants and products. My hypothesis was that the mole relationship between silver and copper will be 2 mol Cu: 1 mol Ag ratio. My hypothesis is supported by the data I found during the lab. First evidence, in the beginning of my calculation I have to determine the mass of copper that reacted during the experiment and converted to moles of copper and got .0033 moles of Cu. Next, I determined the mass of silver produced during the experiment and converted into moles of silver and got .0063 moles of Ag. After I found the moles of copper and silver, I determined the value of the ratio of .0063 moles Ag /.0033 moles Cu and got 1.90 moles. 1.90 mol

Penny A stayed the same, while penny B had a chemical change. The penny started to turn green by the vinegar that was put on it. The vinegar is a chemical and caused the penny to change chemically. Even though the penny still looks like a penny, the reaction from the experiment clearly showed that the change was a chemical change (a substance that is turned into something new). A reason that the penny that was in vinegar changed so much, compared to the penny that was in water is because of oxidation. Oxidation is when metal reacts with oxygen in the air to produce metal oxides. When exposed to air, the metal loses electrons and changes different colors. Due to this, the metal has lost electrons to oxygen, which means the metal has been oxidized. This is how the penny turned a different color. The penny was combined chemically (the vinegar) with oxygen, which made it become oxidized. Penny A stayed the same because the penny was not being affected by anything that was a chemical or an acid, like vinegar. Thus, the penny that was in water was not oxidized and did not turn a green color. Therefore, the reason that Penny B was affected differently than penny A, was becasue penny B was affected by oxidation and was chemically changed, while penny A was

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.

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.

Pennies are made of copper, and when copper gets exposed to oxygen for a long

13) When the tray is thoroughly dry, determine its mass. Record the mass in the data table. You have to wait until day three to weigh the copper.

XIII. Carefully remove the copper metal from the filter paper onto the watch glass. (with a spatula) Place a 400 ml beaker on a hot plate contained with water. Carefully place the watch glass before the water boils to dry the copper metal. (Use the tongs to handle the hot watch glass)

The zinc powder was black in colour while copper (II) sulphate solution was blue in colour because of the presence of copper (II) ions. When the zinc powder was added to the copper (II) sulphate solution and stirred, it was hard to observe the pattern of the colour change because the polystyrene cup as covered with a lid.