Unit 4.2 Chemical Systems in
In this unit teachers are shown using concrete examples
and everyday events to teach about problem solving and the
concept of a chemical system like equilibrium.
Video program cues: 5:30 14:35
"I guess if its a system and its
a chemical system, its got chemistry in it and, depending
on what that system is, there are various aspects and usually
theres a cyclic flow to it, like in the carbon cycle."
"A chemical system
well, I really dont know,
but it could be the combining of one chemical with another,
to make something, combining these two things might be a
chemical system, to make something reactive or something
"And if you ever want to make something you have to
know about chemistry in order to put things together, to
create something totally new, you can create, Ill
make up a word for it, you know, to create electro-magno-pluto
thats something weird, you could give it any
name you want."
Rossi, F. M. (1997)' Writing in an Advanced Undergraduate
Chemistry Course: An Assignment Exploring the Development
of Scientific Ideas, 'Journal of Chemical Education,
Vol. 74, No. 4, pp: 395-396.
Chemistry in everyday life
"Every thing we wear is touched by the
hands of the chemist. The music we hear is touched by the
hand of the chemist. The perfume in the air in Washington
cocktail parties is all chemicals. Chemistry is not going
to go away. What we do have to do is to make sure that both
chemists and non-chemists know a responsible way of working
with chemistry and everything that it can do for us."
American Chemical Society, Washington, D.C.
Teaching based on the familiar
"I think you have to relate it to what
they are used to. Students are used to, for example, chemical
reactions. If you can relate it to dating, which is something
that theyre all very familiar with, different types
of reactions, different couples in a relationship. And when
we do that, the students are very interested in that because
thats something that they are very interested in.
So I think its coming back to their everyday lives."
Watkins Mill High School, Maryland
Parrill, Abby L. (2000)' Everyday Chemical Reactions: A
Writing Assignment to Promote Synthesis of Concepts and
Relevance in Chemistry, 'Journal of Chemical Education
Vol. 77, No. 10, pp: 1303-1305.
Water softening laboratory
Isoke Baptistes students observe that rsoap doesn't
lather up in hard water due to the presence of Mg+2
and Ca+2 ions.
Ceretti, H., Hughes, E. A., Zalts, A. (1999)' The Softening
of Hard Water and Complexometric Titrations: An Undergraduate
Experiment Journal of Chemical Education, Vol. 76,
No. 10, pp: 1420.
to Unit 4.3