MnSTEP Teaching Activity Collection > MnSTEP Activities > Penny Bright Experiment: Does Salt & Vinegar Have An Effect On Pennies?

Penny Bright Experiment: Does Salt & Vinegar Have An Effect On Pennies?

Jarod Werner, Belle Plaine Elementary (Oak Crest), Belle Plaine, MN, based on an original activity from Houghton Mifflin science, pg. E19.


In this lab, students observe and hypothesize, perform the experiment, and observe. We are trying to figure out if a salt & vinegar solution have an effect on tarnished pennies. Students will follow directions to complete their lab. Students will also complete a worksheet, which parallels lab.

Learning Goals

Learning Goals:
- Students will examine a penny and record 5 observations (before/after)
- Students will complete a worksheet that parallels the experiment
- Students will hypothesize pertaining to experiment
Students will use critical thinking skills, synthesizing, and observational skills.

Key Concepts:
- Working with mixtures/solutions
- Discovering the chemical reaction between salt and vinegar

Vocab Words:
- Mixture
- Solution
- Chemical Reaction
- Chemical Change
- Physical Change

Context for Use

Grade Level = 4th-6th
Class Size = Up to 30
Lesson Type = Lab
Time = 10-15 minutes for 2 days and a week later
Equipment = Salt, Vinegar, Cup, Penny, Goggles
Skills = Observational, Hypothesize, and Critical Thinking Skills
Adaptability = Fairly easy

Subject: Chemistry:General Chemistry:Mixtures, Solutions, & Compounds, Chemical Reactions, Chemistry:General Chemistry, ,
Resource Type: ActivitiesLab Activity
Grade Level: Middle (6-8)

Description and Teaching Materials

I'd introduce this project by asking students why they think pennies get so dirty? We'd venture on that for a bit discussing chemical reactions. Tarnish is a chemical reaction between copper and oxygen. We'd talk about if we could possibly clean this penny. Hence the salt and vinegar solution.
You'll need:
Salt, vinegar, cups, and a penny.
Students will follow the directions you've given to them.
To close the experiment we'll discuss things such as the statue of liberty and how she's so tarnished. Do you think we could clean her with some salt & vinegar? While also talking about what happened to the salt and vinegar solution in the cup. This is fun because of the designs and mini structures left behind from the solution after evaporation.
Penny Bright Lesson Plan (Microsoft Word 42kB Aug3 09)
Penny Bright Experiment Worksheet (Microsoft Word 26kB Aug3 09)

Teaching Notes and Tips

I'm going to constantly try to expand on this project. We'll work with variables and how they can be added to or changed.
Safety goggles would be advised to complete this project, just because you'll be working with acids. Also, who knows where most pennies have been. Don't want kids rubbing their eyes after this.


By holding classroom discussions, visiting each group individually at their tables throughout the project, and having the students complete an experiment worksheet.


Grade Level = 6
Strand = Physical Science
Sub-Strand = Chemical Reactions
Standard = The student will differentiate between chemical and physical changes.
1. The student will define chemical and physical changes.
2. The student will observe that substances react chemically with other substances to form new substances with different characteristic properties.
3. The student will give examples and classify substances as mixtures or pure substances.

References and Resources