# Penny Lab Report Essay

Jessica HillisPage 15/15/2008Period 1

Pennies… How dense are they?

Purpose: In this activity, I will determine the density of the metal used in U.S.pennies minted since 1982. This value will be compared to known values pf densities inpublished table so that the metal used can be identified.Hypothesis: I think the penny is made out of zinc with a copper coating to make it look and feel like copper, because after a certain year, I know that the pennies were no longermade out of copper.Background: Density means the degree of compactness of an object. Density is anintensive property because it deals with intensity (pressure and temperature). An intensiveproperty is a fixed value of a substance no matter how much you have. After 1982, the USpennies began to be minted using approximately 99.2% zinc with a 0.8% copper coating.Before 1982, the pennies were made out of almost exactly the opposite (90% copper, 10%zinc).Materials:

•

Scales

•

20 pennies minted after 1982

•

Graduated cylinderProcedure:1. Counted out 20 pennies that were minted after 19822. Placed the pennies on a scale and weighed them all at once3. Placed the 20 pennies into a graduated cylinder4. Took the mass and volume discovered and divided the mass by the volume to findthe density.Observations:1. First, we noticed that all the pennies were minted before 19822. Then, we weighed the pennies all at once and found that the mass of the bunchwas 49.9 grams3. Then, we filled the graduated cylinder with water and tested the pennies volumeand got 7mL, which also equals 7 cm

3

## Determining The Percent Copper and Zinc in Pennies From Density

1208 WordsNov 9th, 20145 Pages

Determining The Percent Copper and Zinc in Pennies From Density

Purpose:

Practicing determine the density of the solution.

Developing the method for determine the percent of density for the solution.

Examining the linear relationship by learning to use the best-fit straight line.

Using the linear relationship to determine the percent of density by the solution.

Be familiar with recording data and observations.

Methods & Material:

Methods:

Weight the mass for the different percent of zinc and copper mixtures, which have 11 groups.

Determining the volume of the zinc and copper mixtures each, and record the data.

Using equation get the density of the pennies. Compare the results.

Find the best-fit straight line.

Material:*…show more content…*

Then calculate the error%=0.01%, and the deviation%=9.74%.

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%.

Part2: Post-82 Pennies Weight 10 dry Post-82 pennies which get 24.91g, using 30ml initial volume measuring the volume of 10 pennies, record the data 3.2ml. Using equation Density= Mass/Volume, get the density of the post-82 pennies is 7.78g/ml. Then calculate the error%=0.04%, and the deviation%=1.60%. Weight 10 dry post-82 pennies which get 52.31g, using 30ml initial volume measuring the volume of 10 pennies, record the data 7.0ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 7.47g/ml. Then calculate the error%=0.08%, and the deviation%=5.53%.

Weight 10 dry post-82 pennies which get 77.12g, using 30ml initial volume measuring the volume of 10 pennies, record the data 9.1ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 8.47g/ml. Then calculate the error%=0.04%, and the deviation%=7.13%.

Part3: Mixture Zn & Cu 100% Zn:

Weight one piece of Zn, got 4.64g. Using 20ml initial volume measuring the volume of Zn, record data 0.7ml. Using equation Density=Mass/Volume, get the density of 100%Zn is 6.63g/ml.

b. 80%Zn & 20%Cu.

Show More

## 0 Replies to “Penny Lab Report Essay”