Return to Chemistry IndexJust How Thick Is Aluminum Foil Anyway???

Patricia A. Riley Lincoln Park High School

2001 N. Orchard Street Mall

Chicago, IL 60614

312-534-3180Objective:

To determine the thickness of a sheet of aluminum foil from the density of

aluminum metal.Materials needed:

Class: Each group of 2 or 3:

aluminum metal shavings balance

variety of brands of aluminum foil metric ruler

demonstration vernier caliper vernier caliper

rolling pin rectangular aluminum metal slab

graduated cylinder, 50 mL rectangular piece of aluminum foilStrategy:

1. Pass 3 or 4 different brands of aluminum foil in boxes (e.g. Reynolds

Heavy Duty, Reynolds Aluminum Foil, Heritage House Heavy Duty, generic aluminum

foil, etc.) around for students to examine. Ask in what ways the brands differ

from each other. What is meant by "heavy duty"? Net weight and the foil

thickness are not printed on the boxes. Ask students for suggestions for

determining these.

2. Review the use of a vernier caliper using the large demonstration model

and boxes of the foil. Ask students to come up and read the calipers. Would

the calipers be useful in finding the foil thickness? They should explain.

3. Review the concept of density which relates the mass of the substance to

its volume. What is the mathematical formula for density? Does density depend

on the shape of the solid aluminum? Show students aluminum shavings and a

rectangular aluminum slab.

4. Have students test out their answer for density by finding the density of

a rectangular aluminum slab at their lab station, recording their data and

calculations in their lab notebook and then writing their experimentally

determined density on the board. Determine the class average density for the

aluminum slabs and compare it to the experimental value for the aluminum

shavings that they determined in an earlier lab. Have a student look up the

theoretical density for aluminum in theCRC Handbook of Chemistry and Physics.

5. Now have the students experimentally find the thickness of their piece of

aluminum foil, recording data and calculations in their notebooks. All groups

have the same brand and thickness of foil. Have a rolling pin and graduated

cylinder available for students wishing to verify the volume by water

displacement. Record their answers on the board and calculate the average.

6. Students write answers for the following questions in their lab report:

A. What precautions must be taken when massing the foil?

B. Why won't water displacement work well for finding the foil's volume?

C. You are given a chunk of shiny silver-colored metal. How can you

tell whether the metal is silver, platinum or aluminum?

D. Describe how the thickness of the metal in the side of an aluminum

pop can can be determined.

E. From the information printed on the box of the aluminum foil, describe

how you might verify your experimentally determined foil thickness.