Name: ______________________________________________

Name:_____________________

Date:______________________

Group Members:______________________

______________________

______________________

Rust RaceDay 1Objectives

Copy the objectives of this experiment from the board (3 pts). From Lesson Plan

1. __________________________________________________________________

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2. __________________________________________________________________

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3. __________________________________________________________________

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Introduction

Metal corrosion, or oxidation, involves the transfer of electrons from the metal to oxygen.

The rate of metal corrosion is affected by such things as exposure to salt, acid, base, and

pollution. A metal can be protected from corrosion by being coated with paint, a rust

inhibitor, or any other film which prevents exposure of the metal to oxygen or moisture.

Galvanizing is used to protect iron and steel products from being corroded. Galvanization

is the application of a thin coating of zinc to iron or steel. In this experiment you will test

metals for oxidation, measure oxygen consumption during corrosion, and identify ways

to protect metals from being corroded.

Safety

1. Always wear safety goggles to protect your eyes.

If you get a chemical in your eyes, immediately flush the chemical out at

an eyewash station. Notify a teacher immediately.

2. Do not allow chemicals to contact skin or clothing.

Name: ______________________________________________

If you get a chemical on your skin, wash it off immediately at the sink

with plenty of water. Notify a teacher.

Some of the chemicals used in this lab will eat through clothing. Be

careful not to get any on your clothes.

3. Promptly report spills to a teacher for proper clean up.

4. Notify a teacher if glass is broken so it can be disposed of properly.

5. Write a short essay about the safety demonstration. What did the demonstration

teach you about eye safety? Did this demonstration give you a reason to change

you lab safety practices? This essay is expected to be 100-150 words long (15

pts).

The eye looked healthy and showed little change in the saline (contact) solution.

The bleach solution caused the eye to turn yellow, shrink, and look very hard or

tough, like overcooked meat. The NaOH caused the white of the eye to turn

transparent and appeared to dissolve. The veins stood out bright red. The HCl

caused they eye to disintegrate.

Materials

Galvanized nails, 6

Iron nails, 6

Paper clips, 6

Pennies, 6

Nickels, 6

2% salt solution

Acetic acid solution

Sodium bicarbonate solution

1 M HCl

1 M NaOH

100 mL beaker, 6

Forceps

Water

Labels

Procedure

Part 1: Testing metals for corrosion

1. Use a pen and the labels provided to label six 100 mL beakers “water,” “salt,”

“acetic acid,” “hydrochloric acid,” “sodium bicarbonate,” and “sodium

hydroxide.” Using a graduated cylinder, pour into each beaker 50 mL of the

solution corresponding to the beakers label.

Name: ______________________________________________

Note: When measuring with a graduated cylinder, place the cylinder flat on the

table and bend at the knees until your eyes are level with the liquid in the

cylinder.

2. Using forceps, place the following into each beaker: a penny, a nickel, an iron

nail, a paper clip, and a galvanized nail. Place the 6 beakers in the lab area

provided and let them stand undisturbed until the next Rust Race lab period,

approximately 1 week.

Name: ______________________________________________

Rust Race 21. Copy the list of materials from the overhead:

Materials

Procedure

Part 1: Testing metals for corrosion

1. During the Day 2 of the Rust Race lab periods, use forceps to remove your test

materials, placing the contents of each beaker on separate paper towels. Carefully

observe each object for any physical changes that may have taken place. Record

any signs of corrosion (loss of shine, change in color, rust) in Data Table 1, which

can be found below (15 pts). In general, corrosion increased with pH. The iron

nail turns reddish brown, the galvanized nail and paper clip turn black, the nickel

turns black, and the penny turns green. At low pH, the galvanized nail, iron nail,

and paper clip may also disintegrate.

DATA TABLE 1: TESTING METALS FOR CORROSION

Test

Material

Iron Nail Galvanized

nail

Paper clip Nickel Penny

Water

Shine

Color

Rust

Salt Solution

Shine

Color

Rust

Name: ______________________________________________

Acetic Acid

Shine

Color

Rust

Hydrochloric

Acid

Shine

Color

Rust

Sodium

Bicarbonate

Shine

Color

Rust

Sodium

Hydroxide

Shine

Color

Rust

Part 2: Measuring oxygen consumption during metal corrosion

1. Use a pen and the labels provided to label two test tubes “Steel Wool” and

“Control.”

2. In a 100 mL beaker, mix 10 mL of concentrated bleach with 20 mL of water.

3. Measure out 1 g of steel wool to the nearest 0.1 g. Rinse the wool with bleach to

remove any rust inhibitors it may contain. This will allow oxygen to access the

surface of the metal for oxidation to take place.

4. Pull apart the strands of steel wool so they are loosely packed and fluffy. Fill the

bottom third of the test tube labeled “Steel Wool” with the loosely packed steel

wool. The steel wool should make contact with the sides of the test tube and

should not slide out when the tube is inverted.

Name: ______________________________________________

5. Measure 1 g of shredded paper to the nearest 0.1 g and use it to fill the bottom

third of the test tube labeled “Control.” The paper should make contact with the

sides of the test tube and should not slide out when the tube is inverted.

6. Pour about 200 mL of water in the 400 mL beaker. Invert the test tubes prepared

in steps 4 and 5 and place them open end down in the beaker. The test tubes

should rest against the side of the beaker and the open ends should be fully

beneath the water level.

7. Use a wax pencil or permanent marker to mark the water level inside each test

tube. Use a metric ruler to measure the height of the water in each tube in cm to

the nearest mm. Also measure the height of the tube above the water. Record

your measurements in Data Table 2, which can be found on the next page. Leave

your setup undisturbed until the next Rust Race lab period (10 pts).

DATA TABLE 2: MEASURING OXYGEN CONSUMPTION

Measurement Test Tube with Steel

Wool

Test Tube with Shredded

Paper

Height of test tube above

water level (cm)

* *

Height of water at start

(cm)

* *

Height of water level on

Day 3 (cm)

Water level increase (cm)

Percent increase in water

level

Percent oxygen consumed

by volume

Initial mass (g)

Final mass (g)

Change in mass (g)

Name: ______________________________________________

Analyzing Data

1. According to your observations in Data Table 1, which solution caused the most

corrosion in the materials tested? Explain why in 3 – 4 sentences (5 pts).

Corrosion is an electrochemical process involving an anode (a piece of metal that

readily gives up electrons), an electrolyte (a liquid that helps electrons move) and

a cathode (a piece of metal that readily accepts electrons). When a piece of metal

corrodes, the electrolyte helps provide oxygen to the anode. As oxygen combines

with the metal, electrons are liberated. When they flow through the electrolyte to

the cathode, the metal of the anode disappears, swept away by the electrical flow

or converted into metal cations in a form such as rust.

HCl causes the most corrosion. In acidic solutions, the metals readily give up an

electron to the H+ ion in solution changing their valence state and giving them a +

charge. This makes it easier for oxygen dissolved in the solution to react with the

metals to form rust, and thus accelerates the reaction.

2. According to your observations in Data Table 1, which solution caused the least

corrosion in the materials tested? Explain why in 3 – 4 sentences (5 pts).

NaOH is the least corrosive. Strong bases do not allow electrons to be liberated

from the metals since there is and excess of electrons in the basic solution.

3. What metal experienced the least corrosion overall? Why? (5 pts)

Silver experienced the lease amount of corrosion overall. Silver requires sulfides

to react with it in order to produces its tarnished layer. Sulfides are not abundant

in aqueous solutions, such as the ones used in this experiment, so the silver did

not corrode as much as the other metals.

Name: ______________________________________________

Day 3Materials

Clear nail polish

Iron nails, 4

Petroleum jelly

Rust inhibitor

100 mL beaker, 1

50 mL graduated cylinder

Balance

Forceps

Metric ruler

Water

Labels

Procedure

Part 2: Measuring oxygen consumption during metal corrosion

1. Use a ruler to measure the new water level in each test tube. Record your results

in Data Table 2, which can be found above.

2. What happened to the water level in each test tube? Why? (5 pts)

The water level in the test tube should rise in order to equalize the pressure within

the tube as oxygen is consumed in the redox reaction to corrode the steel wool.

3. Using forceps remove the steel wool from the test tube and determine it’s mass.

Record your results in Data Table 2. Using forceps remove the shredded paper

from the test tube and determine it’s mass. Record your results in Data Table 2.

Carefully observe the steel wool strands and shredded paper. Describe any

corrosion that has taken place.

Observations (5 pts):

Corrosion should occur. The steel wool should become reddish brown and very

brittle. It should gain mass due to the oxygen atom that have chemically reacted

with the steel to form rust.

Part 3: Protecting metals from corrosion

1. Obtain 4 iron nails. Thoroughly coat the entire surface of the first nail with

petroleum jelly, coat the second nail with rust inhibitor, coat the third nail with

nail polish. Leave the fourth nail uncoated; it is your control.

Name: ______________________________________________

2. Pour 50 mL of salt solution in a 100 mL beaker. Using forceps, place the nails in

the beaker. Be sure the nails do not touch each other. Place in undisturbed area

of laboratory until the next Rust Race lab period.

Organizing Data

1. Calculate the water level increase for each test tube in Part 2 by subtracting the

initial height of the water from the final height of the water. Record your results

in Data Table 2. Show all work below (3 pts).

2. Calculate for both test tubes the percentage increase in the water level by dividing

the change in the water level by the height of the test tube above the water, then

multiply by 100. Record your results in Data Table 2. Show all work below (3

pts).

3. Calculate the change in the mass of steel wool by subtracting the initial mass of

steel wool from the final mass of steel wool. Record your results in Data Table 2.

Show all calculations below (3 pts).

Name: ______________________________________________

4. Calculate the change in the mass of shredded paper by subtracting the initial mass

of shredded paper from the final mass of shredded paper. Record your results in

Data Table 2. Show all calculations below (3 pts).

Inferring Conclusions

1. Based on your calculations for Part 2, what is the percentage of oxygen consumed

by volume in each test tube? Please show any calculations (5 pts).

The change in height of the water is the same as the change in height of oxygen.

Subtract the initial height of the water from the height of the test tube to find the

height of air. The initial height of oxygen is 20% the height of air. Divide the

change in the height of oxygen by the initial height of oxygen and multiply be 100

to find the percent change in oxygen.

Analyzing Data

1. Explain why steel wool gained mass in Part 2 (5 pts).

Oxygen atoms chemically bind to steel wool in the corrosion process. Since

oxygen atoms have mass, the mass of the steel wool is increased.

Day 4Materials

Forceps

Paper towels

Name: ______________________________________________

Procedure

Part 3: Protecting metals from corrosion

1. Use forceps to carefully remove the nails from the beaker. Lay the nails on

separate paper towels. Carefully observe each nail for any physical changes that

may have taken place. Record any signs of metal corrosion in Data Table 3,

which can be found below (10 pts).

The control nail should show the most corrosion. Nail polish should look better

than the control (it will have a few shiny spots) but still show significant

corrosion. If the petroleum jelly nail coating is thin, it may show more corrosion

than the rust inhibitor nail and if the petroleum jelly layer is thick it may show

less corrosion than the rust inhibitor nail. Neither of theses should show a

significant amount of corrosion.

DATA TABLE 3: PROTECTING METALS FROM CORROSION

Test material Shine Color Rust

Iron nail (control)

Iron nail coated

with petroleum

jelly

Iron nail coated

with nail polish

Iron nail coated

with rust inhibitor

Designing Experiments

1. The tarnish of silver is an oxidation reaction between silver and sulfur in the air or

in certain foods. Identify a food that contains sulfur and design an experiment to

demonstrate the tarnishing of silver (10 pts).

Cabbage, tomatoes, grapes, mustard, and other highly acidic foods contain sulfur.

The silver should be covered with a sulfur containing food, sealed, and allowed to

rest for about 1 week in order to make observations. This question allows for a

Name: ______________________________________________

lot of creative thought, so points should be given on thoroughness and correctness

of thought processes.

2. Design an experiment to determine which brand of steel wool resists rusting the

longest (10 pts).

This experiment should test different brands of steel wool similar to how the

initial steel wool experiment was done. The less mass the steel wool gained, the

less it corroded. For the purpose of control, the same mass of steel wool,

regardless of brand, should be used in each test tube.

3. Design an experiment to determine the effects of temperature on oxidation rate

(10 pts).

This experiment will use the same metal, such as a nail, in the same solution for

control purposes. The solution may be stored for a week in a freezer, refrigerator,

at room temperature, in a hotbox, if available, or in a greenhouse type

environment. Students should be sure to take temperature measurements at the

beginning, middle, and end of the experiment.

Engineering Applications

1. Write a 100-150 word essay on why you think it is important for engineers and

scientists to understand corrosion (15 pts).

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__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

Name: ______________________________________________

__________________________________________________________________

__________________________________________________________________

2. You have been asked to design a unit to separate the solutions in this experiment

from one another. Which of the metals tested will you choose to make your

separation unit out of and why? (10 pts)

Students should use the metal with the least amount of corrosion in acid,

especially if this is the least corrosive overall. Silver, maybe copper, would

appear to be best. Extra points may be given to students who consider the

economic impact or mention using cheap materials plated with silver or copper.

Day 5You are now an engineering working in a research facility. With your group members,

design an experiment to test a question or theory you have on corrosion. You may use or

modify the experiment design questions from Day 4. Write a proposal with in

introduction about why you are doing the experiment, important theory that is applicable

to the experiment, a list of materials needed to carry out the experiment, and step-by-step

procedure. This experiment proposal is to be handed to your boss in at the end of the

class so it can be approved, suggestions made, and materials prepared. This assignment

is worth 30 pts.

Introduction

Using previous Rust Race activities and your book, write 7 – 10 sentences about

corrosion. A good starting sentence might be a definition of corrosion.

Purpose

What are the goals of your experiment? Write out 2 – 3 objectives for your experiment.

Briefly discuss (2 – 3 sentences) why your procedure is the best choice for meeting the

objectives you defined.

Safety

List 3 safety rules that must be followed during your experiment.

Name: ______________________________________________

Materials

List the materials and equipment you will need to complete your proposed experiment.

Procedure

Write out the step-by-step procedure for your experiment. These steps should be detailed

and clear so that anyone could walk into a lab and complete the experiment. This should

be quite long, ½ of a page to a page or more, handwritten. You must include a Data

Table in this section that would be filled out during the experiment.

Feasibility

You are writing this to your “boss,” and in business the cost of an experiment determines

whether or not the experiment will actually be conducted. Discuss the relative cost of

your materials. Are they cheap and available at WalMart, or are they expensive and hard

to get? Is the equipment you need already available in the lab or does it need to be

purchased?

Conclusion

Write a 4-6 sentence conclusion. What do you think will be the final result of the

experiment? What did you learn in the process of writing your experimental proposal?

Day 6Carry out the experiment that you proposed on Day 5, taking into consideration your

bosses’ suggestions and changes. It is important that you write down any changes you

make to the experiment as you proceed. It is also important that you keep a data table

with all observations and results. You will need this information to write the lab report,

not to mention your boss may fire you if you are irresponsible with your lab practices.

Your procedural changes, data, results and observations are worth 30 pts.

Day 7You will be given this class period to write the final lab report that you will give your

boss. It should include a title page with the experiment title, your name, your group

Name: ______________________________________________

members’ names, and your bosses’ names (Dr. Lee-Alvarez and Miss Behymer). It also

need to include an introduction that explains why you did the experiment and what

question or theory you were testing. Next should be the experimental procedure you

used, which will be similar to your proposed procedure, but include any changes you had

to make during the experiment. Include a table of data and results, and finally discuss

you data, results, and observations and draw conclusions about what you found out. Did

you answer your question? Was your theory proven true or false? This needs to be

handed in to your bosses at the end of class. It is worth 30 pts.