Science Buddies: "Ask an Expert"

this is the science exprement that i am doing

Prepare four test tubes with tap water, four test tubes with salt water and four test tubes with vinegar. Cut twelve lengths of wire, three of each type, zinc, copper, steel and aluminium. Prepare three pencils by wrapping one type of each wire so that four wires hang from each pencil. Place one pencil so that four wires hang in the tap water, one pencil so that four wires hang in the salt water and place one pencil so that four wires hang in the vinegar. Observe the changes in the wires over a ten day period and record the changes in an observation log.

i need to know how i can make a graph out of this exprement

That's a tough one. Your biggest problem is how to measure the amount of corrosion on each of the wires. Once you have that, it should be easy to graph the results.

I don't know of any particularly good ways to do that, but one possibility is that you could measure the diameter of the wires before corroding them and after the corrosion is complete. However, corrosion may (probably does?) increase the diameter of a wire, so in order to see how much metal was affected you might try removing the corrosion with steel wool and measure the wire diameter afterwards.

However, I'm a software guy, so take my suggestions with a grain of salt .

Hi,

Oxidation or a metal consumes oxygen, so you can measure the loss of oxygen during the chemical process. Here is a website that shows a typical experimental set-up for this type of measurement:

http://www.geocities.com/CapeCanaveral/ ... -P-09.html

Let us know if you have any questions.

Best regards,

Donna Hardy