ELECTROCHEMICAL WRITING AND PRINTING: OVERHEAD PROJECTOR DEMONSTRATION


DEMİRİ S.

CHEMISTRY: BULGARIAN JOURNAL OF SCIENCE EDUCATION, vol.15, no.2, pp.101-108, 2006 (Journal Indexed in SCI Expanded)

  • Publication Type: Article / Article
  • Volume: 15 Issue: 2
  • Publication Date: 2006
  • Title of Journal : CHEMISTRY: BULGARIAN JOURNAL OF SCIENCE EDUCATION
  • Page Numbers: pp.101-108

Abstract

One of the most difficult subjects for students is the concept of

oxidation-reduction. The terms .oxidizing. and .reducing agent. are hard to

understand and usually mixed-up by students. Electrochemistry experiments

could be helpful in making easier to understand this subject. There are many

experiments that demonstrate electrolysis phenomena. However, the experiments

we propose are simple, cheap and could be applied in any level of chemical

education starting from a kindergarten up to the university level. Electrochemical

writing is an electrolysis experiment which shows writing with an electrode

(metal) on a paper soaked with an appropriate electrolyte solution in a

close current circuit. For performing electro-printing experiments, various coins

and other metallic objects are collected. Then, a square piece of aluminum foil

is cut and placed on the top of a rubber surface (rubber sheet). Quantitative

(smooth) filter papers are placed on the aluminum foil and soaked with different

kinds of solutions: aqueous solutions of ammonia, potassium hexacyanoferrate(

II), potassium tiocyanate, potassium iodide or solutions of sodium

sulfate with different acid-base indicators (including natural red cabbage

indicator).