How To Get CosheCom For A Month

Free Essay, Research Paper

Vlad Shvorin FCAs

10/15/01 1. Use of Scientific Terms

2. Use of significant figures.

3. Content

The purpose of this lab is to find the difference between pennies made before and after 1982. This lab includes seven steps, they re listed below:

1) Using a balance, determine the mass of 20 pre-1982 pennies.

2) Repeat Step 1, except use 20 post-1982 pennies this time.

3) Pour 50 ml of water into a graduated cylinder and put the pre-1982 pennies in. Find the volume of pennies and do it twice more (dry of the pennies before putting them back).

4) Follow the same process as in #4 with post 1982 pennies.

5) Determine the average density of each set.

6) Review your data for any large differences between trials.

7) Compare the average experimental densities of the two sets of pennies with the densities of the metals listened in the Appendix Table A-14, Properties of Common Elements.

*TRIALS* 1 PRE 19822 3 1 POST 19822 3

Mass 60.97g 60.989g 60.98g 50.20g 50.26g 50.20g

Volume Pennies 57ml 56ml 56ml 56.5ml 58ml 56.5ml

Density 1.06g/ml 1.08g/ml 1.08g/ml 0.88g/ml 0.86g/ml 0.88g/ml

Avg. Density 1.07g/ml .87g/ml

The results were very clear. The pre-1982 pennies had a higher volume & density then the post-1982 pennies because of the materials they were made of.[1] It s necessary to repeat the process 3 times because it would minimize the chance of having incorrect or inaccurate data.[2a] If a set of data is abnormally high or low, then it would usually be inaccurate.[2b] Accidents can occasionally happen and they would usually be responsible for inaccurate data.[3] Based on the physical composition and the experimental data, I can conclude that pre-1982 pennies have a high volume, density, and are made of different (heavier) materials.