MHS Chemistry
Qualitative Analysis of Pennies

Introduction

In this experiment, you will be carrying out a qualitative chemical analysis of old pennies and of new pennies (these groups are as determined in the previous lab about pennies).  "Qualitative" means that you will be making careful observations, but not making any numerical measurements.

Safety! 

  1. Concentrated acids can cause severe burns.  You must wear goggles during this lab.
  2. Follow your instructor's directions to light the bunsen burner, or a dangerous gas build-up and explosion may occur.
  3. Use only minimum amounts of each material.  Some of the reactions produce a gas that is toxic in large amounts, but dissipates easily from smaller amounts.
Materials
You will be given an two "new" pennies, one "old" penny, and samples of several pure metals, all of which are clearly labeled.  The metal samples will include the actual materials of which pennies are made.  In addition, you will have the following materials/tools to apply to each sample:
super-shears concentrated nitric acid
bunsen burner concentrated hydrochloric acid
iron wool (for scrubbing) concentrated sulfuric acid
sodium sulfide solution ammonia solution
magnet water

Procedure - Qualitative Analysis of a Penny
See how each sample material and the old and new penny react to each of the test liquids.  Use the minimum amount of each material possible for each test.  To see if a metal is soluble in a liquid, place the metal sample in a small clean test-tube, then add a few drops of the liquid in question.  Record any observations.  After a few minutes, dispose of the liquid in the waste jar, and rinse the test tube thoroughly.  If the metal is not damaged, save it for the next test.  Examine the metal for pitting or etching, and record your observations.

Besides the three pennies issued, further tests are at your own expense!  Use your common sense (ha ha).

All acid waste should be disposed  of according to your teacher's instructions.  Thoroughly clean your lab bench with a sponge dipped in soapy water at the front sink.

Analysis
Construct an observation table to present your results.  You should be able to compare every metal and both pennies for each test.  Write a paragraph telling which of the metals tested best matched the reactions of the old pennies, and of the new pennies.  Do these results agree with your previous lab?  You may wish to refer to your previous penny lab.

Student Learning Expectations
A2 - A Middletown High School graduate will acquire, analyze, and evaluate information and ideas to effectively solve problems.
S1 - A Middletown High School graduate will demonstrate responsibility for his or her own actions, behaviors, and academic success.
S2 - A Middletown High School graduate will work cooperatively to achieve group goals and resolve issues.
3
  • Complete title section
  • Clear & appropriate purpose or hypothesis.
  • If necessary, procedure included as numbered list, or properly referenced.
  • Data & Observations properly recorded and presented, few decimal errors, most labels present correct.
  • Graphs are present & accurately constructed, if required.
  • All calculations are shown for one trial, and every value includes description, number, and label.
  • Analysis and Questions section(s) complete, correct, clear, and written with proper spelling and grammar.
  • If necessary, the purpose or hypothesis is specifically addressed.
  • Lab is neatly written in dark ink, few cross-outs, stapled in top left corner OR two sides of one sheet, sections in correct order, no notebook "fuzz," few grammar or spelling errors
  • If the lab is late/unexcused, the maximum score possible will be a 3, regardless of the quality of the work.  Even if you would otherwise get a 4, a perfect late lab can never score higher than 3.  You have been warned!

[Analysis of Pennies score sheet][General Lab Rubric][MHS Chem page]