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Asia-Pacific Forum on Science Learning and Teaching, Volume 17, Issue 1, Article 8 (Jun., 2016) |
Research Design
This study was a mixed method design which included both the quantitative and qualitative approach. For the quantitative approach (survey), 60 Form Four students from two secondary schools in Sibu, Sarawak were selected to answer an open-ended electrochemistry assessment. For the qualitative approach (case study), ten students were selected from the 60 students to take part in the interview. The purpose of the interview was to find out the factors which contributed to the students’ misconceptions in analysing the electrolysis of molten compounds and aqueous solutions.
Respondents
The respondents of this study consisted of Form Four students from two secondary schools in Sibu, Sarawak who were taking the subject of Chemistry. The two schools were selected from 24 schools in the Sibu district based on the cluster sampling method. All the Form Four students who studied Chemistry from the two schools participated in this study, making the total number of respondents 60 students. After all the respondents had answered the open-ended electrochemistry assessment, ten respondents were selected for the interview using the purposive sampling method. The respondents selected for the interview were those who were having misconceptions in the open ended electrochemistry assessment.
Two instruments were used in this study, namely the open-ended electrochemistry assessment and interview protocol.
Open-ended Electrochemistry Assessment
An open-ended electrochemistry assessment (Appendix A) consisting of two structured questions was used to identify the students’ misconceptions in analysing the electrolysis of molten compounds and aqueous solutions. The questions were developed by referring to the text book (Low, Lim, Eng, Lim & Ahmad, 2005) and previous studies (Acar & Tarhan, 2007; Bakar & Mukhtar, 2011; Bakar & Tay, 2010; Sanger & Greenbowe, 1997). KR-20 value for the open-ended electrochemistry assessment was reported to be 0.816. Table I shows the distribution of questions based on the common misconceptions in electrochemistry.
Table I. Distribution of Questions Based on the Misconceptions in Electrochemistry
Misconceptions
Distribution of Questions
Sample Questions
Identifying Cathode and Anode
- In the electrolytic cells, the polarity of the terminal of the applied voltages has no effect on the site of the anode and cathode.
- The identity of the anode and cathode depends on the physical placement of the half cells.
- The anode is negatively charged and because of this it attracts cation. The cathode is positively charged and because of this it attracts anion.
1a), 1b), 1c), 1e(i), 1e(ii), 2a(i), 2a(ii), 2d(i), 2d(ii)
- Does the polarity of batteries affect the position of the anode and cathode in the diagram above?
- How would you determine the anode and cathode of the electrode?
Reaction in the Electrolysis of Molten Compounds and Aqueous Solutions
- The same products are produced in both aqueous and molten situation of electrolysis.
- Water does not react during the electrolysis of an aqueous solution.
- Metal electrodes only act as an electron carrier during the redox reactions and there will be no changes in the physical structures of the electrodes.
- Inert electrodes can be oxidized and reduced.
- When two or more oxidation or reduction half reactions are possible, there is no way to determine which reactions have occurred.
1d), 1g(i), 1g(ii), 2b(i), 2b(ii), 2c), 2e(i), 2e(ii), 2f(i), 2f(ii), 2f(iii), 2g(i)
- If the electrolyte is changed to aqueous potassium iodide, what are the ions involved in the electrolysis process?
- Does water take place in this reaction?
- Can carbon electrode take place in this electrolysis reaction? Why?
Writing Chemical Equations
- Cannot remember the oxidation state of the ion.
- Cannot balance the equation.
- Confused on which ions accept electrons and which release electrons.
1f), 2f(iii), 2e(i), 2g(iii)
- Write the half equation for the anode and cathode.
- Write the half equations for the reactions at electrode X and electrode Y
Interview Protocol
The purpose of the interview was to assess the students’ point of view on why they were having misconceptions in learning electrochemistry. The information collected from the interview was used to identify the sources of misconceptions and this helped to support the findings of the quantitative research.
The main objectives of this study are to identify the students’ misconceptions and factors contributing to the students’ misconceptions in analysing the electrolysis of molten compounds and aqueous solutions. Thus, we constructed an open-ended assessment to identify the students’ misconception through their answers in the assessment. On the other hand, the factors which contributed to the students’ misconceptions were identified through the interview.
We carried out the open-ended electrochemistry assessment after school hours to avoid disturbing the students’ lesson time. Respondents were notified a week before the assessment was given so that they would have ample time to carry out their revision on the topic tested. This was also to ensure that the respondents were well prepared for the assessment.
After answering the questions, the respondents’ answers were marked based on the answer scheme. The students’ answers were marked as correct if they were able to explain the answers they had given in the assessment questions. If students were unable to explain correctly based on the answers they had given, they were categorized as having misconceptions in the topic tested. Later, the percentage of each misconception was calculated.
For the qualitative design, we applied the purposive sampling method to select students who were having misconceptions in the open-ended electrochemistry assessment to participate in the interview session. The purpose of the interview was to determine the factors which led to the students’ misconceptions.
