Creative Education
2013. Vol.4, No.7, 446-451
Published Online July 2013 in SciRes (http://www.scirp.org/journal/ce) http://dx.doi.org/10.4236/ce.2013.47064
Copyright © 2013 SciRes. 446
Usefulness of Plastic Hoffman Apparatus in Chemistry Classes: A
Case Study of Its Implementation with High School Teachers
Muhamad Hugerat
*
, Ahmad Basheer, Naji Kortam
SALiS Center, The Academic Arab College for Education, 22 Hachashmal St., Haifa, Israel
Email:
*
muha4@macam.ac.il
Received April 12
th
, 2013; revised May 13
th
, 2013; accepted May 22
nd
, 2013
Copyright © 2013 Muhamad Hugerat et al. This is an open access article distributed under the Creative Com-
mons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, pro-
vided the original work is properly cited.
In this article we present simple and feasible idea to introduce electrolysis experiments using accessible
materials in the classroom. We use plastic syringes and pipettes to build different shapes of Hoffman ap-
paratus for electrolysis. This activity was introduced to a group of 20 teachers from the Arab sector in Is-
rael to examine their impressions about the activity and investigate the feasibility of implementing the ac-
tivity in their classrooms.
Keywords: Electrolysis Workshop; Professional Development of Teachers; Case Study; Accessible
Materials; Plastic Apparatus
Introduction
Professional development of educators at different levels is
described by many researchers as a central lever leading to
change and improve the capabilities and achievements of the
education system (Scandholtz & Scribner, 2006).
Elliote (1999) emphasizes that it is very important to carry-
out local studies, and case studies to examine the interaction be-
tween local and global dimensions related to the development
of teachers.
Teachers can act as powerful mediators in introducing
change. Their decision to implement a new project depends on
their satisfaction from the current situation and their expecta-
tions from the contribution of the project in improving their tea-
ching (Wallace & Louden, 1998; Zidani, Kortam, & Hugerat,
2003).
In order to introduce a change, the teacher, himself, must go
through a learning process (Wheeler et al., 1995). In this proc-
ess, the teacher is an active partner in the creation of change.
This involvement is a constructivist teaching model, which is
essential in the introduction of such process.
In a study among elementary school teachers in Israel, Ben-
Chaim et al. (1994) found that training workshops encourage
the implementation of approaches, attitudes and scientific—
technological—and social literacy among the participating tea-
chers.
In this article we present simple and feasible idea to intro-
duce the microscale electrolysis experiments using accessible
materials in the classroom. We use plastic syringes and pipettes
to build different shapes of Hoffman apparatus for electrolysis.
We introduce this activity for high school teachers and we ex-
amine the impact of this implementation.
Starting from the last century, electrolysis of water solutions
has been widely demonstrated to students in secondary schools,
or in a first-year college in order to illustrate oxidation-reduc-
tion reactions as well as to demonstrate the use of an external
source of energy for driving non-spontaneous chemical reac-
tions (Hendricks & Williams, 1982; Hugerat, 2006, 2008; Hu-
gerat et al., 2009; Shakhashiri, 1992; Zhou, 1996).
A Hofmann apparatus is an apparatus for electrolyzing water,
invented by August Wilhelm von Hofmann. It consists of three
joined upright cylinders, usually glass. The inner cylinder is
open at the top to allow the addition of water and an ionic com-
pound, such as a small amount of sodium sulfate, to improve
conductivity. A platinum electrode is placed inside the bottom
of each of the two outer cylinders, connected to the positive and
negative terminals of a source of electricity. Gaseous oxygen
forms at the anode and gaseous hydrogen forms at the cathode
when a current runs through the Hofmann’s apparatus. Each gas
displaces water and collects at the top of the two outer tubes
(Hugerat, 2006, 2008; Hugerat & Schwarz, 2008; Hugerat et al.,
2009; Zhou et al., 2005).
Microscale chemistry is the reduction of chemicals use to the
lowest level at which experiments can be effectively performed.
It offers a safer way to perform chemical experiments by using
smaller quantities of chemicals. Microscale experiments are con-
ducted without compromising the quality or standard of chemi-
cal applications in educational institutions and the experimental
industry. The Benefits of Microscale Chemistry are: reduces
chemicals use by promoting waste reduction at the source; im-
proves laboratory safety (air quality, reduced exposure, and
spills); saves money; decreases experiment time; teaches stu-
dents alternatives to conventional chemistry (Singh et al., 1999;
Zhou et al., 2005).
For microscaling, the “Hoffmann Apparatus” the container,
the electrodes, the electrolyte, and the power supply are replac-
ed by smaller units; uses narrow 3-mL test tubes, insulated cop-
per wire (for the anode they are combined with a pencil lead),
diluted sodium hydroxide solution, or sodium sulfate solution
*
Corresponding author.