Pennies Lab Report

2. Collect data: Click Slice. Choose a piece of Styrofoam and drag it onto the Material Investigation tray. Record the mass and volume, then calculate the density by dividing the mass by the volume. Replace the piece, and then repeat for the remaining pieces.

The purpose of this lab is to figure out the mass percentage of copper in a penny. Furthermore, by doing this lab we will practice using a spectrophotometer and review the names of equipment such as volumetric glassware, pipets, and volumetric flasks.

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.

Density was an important part of this lab. Density can be defined as the ratio of the mass of an object to the volume. To find the density of an object, simply divide mass and volume. The equation looks like this: D=M/V. Density is an intensive property that depends only on the composition of a substance, not the size of the sample.

Purpose: Weighing objects. Figuring out the density with an object by calculated volume and Archimedes’ Principle.

This experiment was performed to observe differences in density based on the chemical makeup of an object. Pennies minted before 1982, pennies minted after 1982, and an unknown metal sample was tested to see if there were any differences in their densities. Ten pennies from each category and the metal sample were weighed using a scale to find mass and the displacement method was used to find their volumes. The masses and volumes were then used to calculate the densities of the pennies (D=m/v). The density of the pre-1982 pennies were 8.6 g/mL while the post-1982 pennies were 6.9 g/mL. The metal sample’s density was 1.7 g/mL. Following the experiment we were given the real densities of each item to calculate the percent error with the formula

Weight 30 dry pre-82 pennies which get 89.77g, using 30ml initial volume measuring the volume of 30 pennies, record the data 10.0ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 8.98g/ml. Then calculate the error%=0.10%, and the deviation%=1.29%.

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.

Next, the data was recorded and was used in the formula to find the density of the 40 pennies.

The density of the coins is 8.47 g/cm3 which matches the density of yellow brass the coins recovered are yellow brass

In Measuring and Understanding Density, several experiments were performed to find density of regularly shaped objects, irregularly shaped objects, liquids and gasses. An additional experiment was done to find the specific gravity of a sampling of liquids. The purpose of the experiment was to provide a better understanding of density and to be able to extrapolate unknowns based upon these calculations. The experiments yielded data in keeping with Kinetic-molecular theory in regards to the density of water versus its temperature. Key measurements and formulae were also used to determine densities of metal and plastic objects as well as irregularly shaped rocks. It is possible to find the density of an object (be it liquid, gas or

Did the coin have to be a penny? Explain. I believe that the coin didn't need to be a penny. For this journal, the same quantity of exterior area is needed so if you use pennies, cents or dimes, it does not matter if you use all same coins in the lab, the only thing that would have changed is the amount of drops.

The pennies that were dropped into the graduated cylinder could have caused some of the water to splash out of it. This may have caused an error in measuring the volume, this would have caused the volume measured to be less than the actual volume, thus allowing the density of the pennies to increase, causing the lab results to be uneven. Another source of error has to do with the mass of the pennies. After the pennies were taken out of the graduated cylinders filled with water, there was still some water droplets left on the pennies when put on the triple beam balance. This extra weight of the water may have caused the measurement in the mass of the pennies to be more than they actually were. This outcome could have caused the density of the pennies to be increased as well, making the lab results inconstant. Any type of coating, for example rust, on the penny may affect the mass. This will add to the mass making it higher, and since density is proportional to the mass, the density will be calculated higher than what it actually

As presented in Table 1, only pennies were used in this part of the experiment. 8 pennies were added to the cup at each interval, and in response to the addition, the force consistently increased by 0.20 N. This demonstrated an upward trending linear relationship, as can be seen in Figure 1. The slope, or m, represents the weight of a penny, which, is shown in Figure 1 as 0.025 N. The x-values represent the independent variable, which is the # of pennies, while the y-values represent the dependent variable, force (N). Slope can be represented as the change in the force (N) divided by the change in the # of coins. The value for slope in this data set represents the force per coin. The y-intercept value (b) is 0, which is the y value

What is density? Density is the degree of compactness of a substance. The density formula is D=Mass divided by Volume. While doing this experiment you will need a graduated cylinder, electric balance and water displacement method to find the density of pennies after 1982. Water displacement is the volume in measure of the amount of space an object takes up. The differences between pennies before 1982 and after 1982 is after 1982 the government decided to put less copper because copper was way to expensive. Pennies before 1982 contained 95% copper, zinc 5% so then after 1982 they started using 95% zinc, and 5% copper. The objective of the lab was to find the density of a penny after 1982 to compare how big the difference was from before 1982