I know a lot of you are earning credits toward higher education degrees, working to earn some extra money, or catching up on personal business; but, I hope you’re also getting a chance to relax during this summer of 2017. You’ve earned it!
The book Chemistry on a Budget contains inexpensive chemistry labs that are useful with easy to obtain materials.
There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
You can buy this lab book for $23 at amazon.com or lulu.com. It will take 1-2 weeks to get to you.
It will take a few weeks for the book to get to you, so ORDER NOW! You’ll want to have some time before the school year starts to see how you can use the book Chemistry on a Budget in your class.
*Some of you have already purchased Chemistry on a Budget – be sure to check out Page 141 !
Recently, I was researching for methods to clean rust off a bathroom drain at my home. A few methods using chemicals were suggested, but they were more caustic than I would like to use.
One method that is very effective, just a little slow, was to use aluminum foil to clean rust off the bathroom drain.
Because aluminum is higher on the Activity Series, it will replace the iron of the iron III oxide (rust) in a Single Replacement reaction. The solid iron produced can be rinsed away because very fine particles are the result. If the iron powder remains on the porcelain of the tub or sink, use an over-the-counter cleaner to remove.
What is rust?
“Rusting of iron consists of the formation of hydrated oxide, Fe(OH)3, FeO(OH), or even Fe2O3.H2O. It is an electrochemical process which requires the presence of water, oxygen and an electrolyte. In the absence of any one of these rusting does not occur to any significant extent.”
This page provides the chemical reactions of rust from a Reduction/Oxidation or Redox focus.
Here is a video of aluminum foil and water being used to remove rust on an old bicycle:
Using cola instead of plain water (the cola contains the electrolyte phosphoric acid, H3PO4) with aluminum foil is demonstrated in the following video, but is it the best method?
Another approach is shown in the video below using aluminum powder for greater surface area of the reactants, white vinegar rather than water or cola, added table salt to increase the electrolyte (as stated in the video), and flour to aid polish. An electric polishing pad is used for approximately 2 hours – here is the result:
It was a great result but very time consuming; also, an electric appliance is not safe to use around water (such as a bathtub).
I had a very rusty tub drain to clean. I used very wrinkled aluminum foil (to increase the surface area), white vinegar for acid and polished by hand. I had to clean the iron off the porcelain with an over-the-counter cleaner -- but did not have time for 2 hours. I worked maybe 5-10 minutes.
Vinegar is not a very strong electrolyte (remember, it is a weak acid) so table salt (NaCl) provides more ions to the solution, strengthening the electrolyte.
A very effective method to clean the rust off the tub drain was by increasing the surface area of the reactant aluminum foil by crumpling it loosely and using a stronger electrolyte in the form of a table salt (NaCl) aqueous solution.
The stronger the NaCl solution, saturated if possible, the better. The NaCl isn't a reactant but an important medium for the redox reaction.
(just added 7/17/17) You might want to wear plastic gloves while doing this -- the small bits of iron get under your fingernails and are difficult to clean off.
Overall, this simple method was effective, it was just necessary to keep replacing the reactants -- the aluminum foil and the salt solution – and the method is time-consuming.
This was a much-needed repair in my own home, and I’m very excited that it worked with easily obtained materials (and a little elbow grease). I regret that I did not remember to take before and after pictures!
Here are past posts related to this topic:
01/11/2014 New Schedule
(Single Replacement Reaction –
Cu with Ag)
11/21/2014 Predicting Products of a Single
(3rd Rxn Type)
05/04/2014 Electrochemistry – Redox Basics
05/14/2014 Electrochemistry – Electrochemical
05/21/2015 Natural Cleaners
You could start collecting rusty items or have students contribute to your collection so you could demonstrate this redox reaction in class, it's that immediate!
Also, you might want to offer Extra Credit to your students in researching any cleaning/repair methods using chemical reactions.
*This Blog contains several entries that would be helpful to your chemistry classroom. Check out the Topic List to help you to find past Blog entries.
Also, Write To Me about your successes, challenges, or questions in the Chemistry Classroom.
Remember, buying a copy of the lab book Chemistry on a Budget can be very useful to your Chemistry classroom with labs and class article ideas.
Have a great weekend!