Teaching Resources

Electrolysis, Part 1
Multimedia Lesson

Petinka Galcheva

Downloadable material

Medium

Cooperative learning

Fundamental Chemistry

Lower Secondary School

Bulgarian

Yes

“The Electrolysis” multimedia lesson is designed for use in 8 to 9 grade-level classes in Chemistry and Environment, as part of compulsory or specialized training. It is relevant to the classroom as well as to club and extracurricular activities. It can also find application in Physics or some science subject lessons related to electrolysis. The visualization of the particular processes of the phenomenon contributes to a greater awareness and more effective understanding. The resource provides micro-level based illustration which ensures easier accessibility to students and better interactivity.
The textual part of the multimedia lesson has a guiding and an explanatory function. It helps the natural transition from one video material or comprehension task to another.
The introduction gives an update on the process of interaction between positive and negative charges causing ion discharge to occur. “The Migration of Ions” video film provides a variety of possibilities using electrolysis cell of molten sodium chloride. One of the advantages of the resource is the principle of gradually introducing terms, as electrolyte, electrode, anode and cathode, to learners. Tasks are designed to appeal to students, to help them understand concepts and define with ease the direction of ion movement. A description of the phenomenon precedes a video film that presents the processes using apparatuses for teaching electrolysis. By means of improvised magnifying glass students can observe the processes and the flow of electrons in the cell which constitutes an electric current through the electrolyte. Thus, macro and micro presentations of the experiment can be visually put together. The task that follows is to match terms written in two columns. The interactive effect of the resource is complemented by a “true/false” exercise. False answers are supported by additional information that helps learning in an interesting and attractive manner. Although a bit more complex, the electrolysis in sodium chloride solution is demonstrated in an easy-to-understand way in the video films of “Decomposition of water due to electric current” and “Electrolysis of sodium chloride solution”. To complete tasks for defining the products of electrolysis of different salt solution, students have to use the “Shuffle” command, which changes the electrolyte type only, keeping other elements right. It extends further the range of applicability and the effectiveness of the product. The resource provides a computer simulation of the processes in the electrolysis cell including dynamic animation, which is easily identified with computer games desired by students so much. Computer-simulated processes are full of variety and are easy to understand.
Objectives:
• To enhance young people’s interest for Chemistry and to help effective learning.
• To develop a greater level of motivation and active learning through attractive approaches.
• To attract students attention stimulating them and encouraging self-reliance and adaptability when learning about processes and phenomena on a micro level.
Application:
• For classroom work and extracurricular activities. Suitable for lessons introducing new knowledge, for practice and assessing achievement.
• Provides opportunities of monitoring and self-check during teaching.
• Appropriate for students of science-based interests, stimulating and motivating them further.
• Well accepted by students; facilitates self-study and progress check in an understandable way.

Points of strength:

 visualization of subject matter
 contributes to enhancing interest
 contains glossary of terms
 provides possibilities of practice and progress check
 can be used for self-study
 saves time and resources needed for demo experiments in theory lessons
 easy and fast update of knowledge
 learning while enjoying

Point of weakness:

• Necessity of computer- media aids which some schools can’t afford
• Not easily viewed by each student


The resource has a real scientific and methodological value. It answers the requirements for state-of the-art education appropriately combining audio-video technologies, text and animation.
The resource can be used both in the classroom and for self-study. Suitable for lessons introducing new contents, for practice, reviews and revisions.

technical university Gabrovo