“The ions piggy-back the electrons”: Investigating Students’ Alternative Conceptions in Electrochemistry
Case synopsis
Miss Ting, a student teacher, is going for her first teaching experience by performing a relief session for a JC2 chemistry
class. While eliciting responses from the students on the topic of electrochemistry taught earlier by another teacher, she
discovers that the students have a number of alternative conceptions. The ‘lesson’ can be enacted by student teachers which is
used as a trigger for the student teachers to surface, analyse and clarify both their own and students’ understanding of
electrochemistry or other chemistry topics.
What I Know
1. Students has learnt the topic electrochemical cells.
2. Students do not understand the function of salt
bridges in electrochemical cells.
3. Students have the following alternative conceptions:
• Ions piggy-back electrons as they flow through
the solutions
• Electrons are present in solution and move from
one electrode to the other.
Investigation
Student teachers will enact the classroom
lesson on electrochemistry.
Identify and apply question techniques to elicit
students’ and their own alternative
conceptions on electrochemistry.
21CC: Information and communication skills,
independent thinking, questioning and
reflecting.
Resources: Online search (Pfundt & Duit,
2009) on alternative conceptions in science;
Paper on misconcpetions in electrochemistry.
(http://www.ejmste.com/v5n2/EURASIA_v5n2_Eilks_etal.pdf)
Products: Lesson plans on how to address
alternative conceptions in class; a list of
alternative conceptions in electrochemistry.
What I Need to Know
Will Miss Ting have time to reteach the topic?
What constitutes a current?
What is the mechanism for current conduction in an
electrochemical cell?
How was salt bridge taught in the textbook / lecture
notes?
What are some examples of commonly encountered
salt bridges?
What are some good questioning techniques that
teachers can use to help their students clarify
misconceptions?
Investigation Ideas
Alternative conceptions in chemistry.
Mechanism of current conduction through
solution and salt bridge.
Other ideas for investigations
http://www.chem.umn.edu/services/lectu
redemo/info/cu-zncell.html
Other Useful Resources
Literatures: Journal of Chemical Education, Chemistry
Education Research and Practice, International Journal of
Chemical Education
Online simulations (e.g. Chemistry Online, YouTube
http://www.youtube.com/watch?v=A0VUsoeT9aM;
http://www.dynamicscience.com.au/tester/solutions/chemist
ry/redox/electicalenergy1.htm;
http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electroch
emistry/Voltaic_Cells)
Books on chemistry demonstrations (e.g. Invitations to
Science Inquiry, by Tik L. Liem).
Surface, analyse and clarify both student
teachers’ and students’ understanding of
electrochemistry.
Design lesson plans and assessments to
surface and address students’ alternative
conceptions.
http://www.youtube.com/watch?v=A0VUsoeT9aM