Lasagna Battery (Mara Desso)

Research Question and Hypothesis

How quickly do different tomato sauces react with aluminum foil?

Standards

HS-PS1-1.

HS-PS1-2.

Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms. [Clarification Statement: Examples of properties that could be predicted from patterns could include reactivity of metals, types of bonds formed, numbers of bonds formed, and reactions with oxygen.] [Assessment Boundary: Assessment is limited to main group elements. Assessment does not include quantitative understanding of ionization energy beyond relative trends.]

Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties. [Clarification Statement: Examples of chemical reactions could include the reaction of sodium and chlorine, of carbon and oxygen, or of carbon and hydrogen.] [Assessment Boundary: Assessment is limited to chemical reactions involving main group elements and combustion reactions.]

Experimental Design

  • Cut four 5cm x 5cm pieces of aluminum foil and measure their initial mass.

  • Place a 5cm x 5cm piece of aluminum foil on top of 50ml of 3 different tomato sauces on a plastic plate, leave one sheet on a plate with no tomato sauce as a control.

  • Each day, at the same time, take a picture of each plate. Repeat this for 10 days.

  • At the end of the 10 days, remove the aluminum foil and measure the mass of the DRIED aluminum foil for each plate.

Independent variable

The independent variable is time. It will be measured in days.

Dependent variables

The dependent variable is aluminum foil mass and surface area. The mass will be measured, in grams, at the end of 10 days. Qualitative observations of the surface area will be made throughout the 10 days.

Series

Study the size of aluminum foil (dependent variable) as a function of time (independent variable) from various different tomato sauces (series).

Constants and Controls

Constants include plate type, time of day of measurement, measurement tool, surface area touching tomato sauce, type of aluminum foil, and temperature.

The control will be the piece of aluminum foil that is left on a plate with no tomato sauce.

Materials

  • various different tomato sauces (you may consider testing different sauces)

  • metal pans (you may consider testing different pans)

  • 2 pieces of 5cm x 5cm aluminum foil (same brand)

  • Cell phone camera

  • Balance

  • Weigh boat

Procedures

  1. Place your metal pan on a flat surface.

  2. Label each part of the pan with the type of tomato sauce being used.

  3. Add 2 50ml portions, not touching, of each different tomato sauce brands being tested to each labeled pan.

  4. Cut a 5cm x 5cm piece of aluminum foil for each section of sauce and record the initial mass of each piece.

  5. Place one piece of aluminum foil on each of one type of tomato sauce so that the edge touches the pan. Place one piece of aluminum foil on the other portion of each sauce so that it does not contact the pan at all.

  6. Take an initial photo of each pan.

  7. Take a photo of each plate every day at the same time for ~2 days. If possible, also take the mass of each piece.

  8. At the end of 2 days, pat each remaining piece of aluminum foil dry and measure the final mass of each one.

Sample data and graphs

If tomato sauce is not available, ketchup can be used as a substitute. Make sure you try this out with your particular pan before doing this with your students! This will only work if there is a significant difference in reactivity between the aluminum and your pan.

Deposit two fairly equal size circles of your sauce of choice into the metal pan. Cover one with aluminum foil that touches the metal pan and one with aluminum foil that does not touch the sides of the pan.

Actual Lasagna Pictures:

Sample Data of Aluminum Losing Mass Over Time (Where does the mass go???)

Analysis & Conclusions

The tomato sauce contains vinegar, acetic acid, and citric acid as well as salt. This combination creates an electrolyte solution. The aluminum foil acts as an anode

(loses electrons) while the steel pan acts as the cathode (gains electrons). The aluminum foil will disintegrate as electrons are passed through the electrolyte to the steel pan. This will result in aluminum foil with holes in it!

Photos & Movies