**10. Industrial reaction to produce fertiliser**

Question: According to the following equation, sulphuric acid (H2SO4) reacts with ammonia (NH3) to produce the fertiliser ammonium sulphate ((NH4)2SO4):

(NH4)2SO4 = H2SO4(aq) + 2NH3(g) (aq)

How much ammonium sulphate can be made from 2.0 kg of sulphuric acid and 1.0 kg of ammonia?

Answer

Step 1: Convert the sulphuric acid and ammonia masses into moles n(H2SO4) = m/M

=2000 g/98.078 g/mol = 20.39 mol n(NH3) = 1000 g/17.03 g/mol = 58.72 mol =1000 g/17.03 g/mol = 58.72 mol

Step 2: Determine which of the reactants is limiting using the balanced equation. According to the balanced chemical equation, one mole of H2SO4 reacts with two moles of NH3 to produce one mole of (NH4)2SO4. As a result, 20.39 moles of H2SO4 must react with 40.78 moles of NH3. In this case, NH3 is in excess, and H2SO4 is the limiting factor.

In the following equation, sulphuric acid (H2SO4) reacts with ammonia (NH3) to produce the fertiliser ammonium sulphate ((NH4)2SO4):

H2SO4(aq) + 2NH3(g) = (NH4)2SO4 (aq)

*Implementation of Conceptual Change Approach to Improve Learners' Understanding… DOI: http://dx.doi.org/10.5772/intechopen.114094*

What is the maximum mass of ammonium sulphate that can be obtained from 2.0 kg of sulphuric acid and 1.0 kg of ammonia?

Answer

Step 1: Convert the mass of sulphuric acid and ammonia into moles n.

Step 3: Determine the maximum amount of ammonium sulphate that can be produced.

Answer

According to the equation, the mole ratio of H2SO4 in the reactants to (NH4)2SO4 in the product is 1:1. As a result, 20.39 moles of H2SO4 will produce 20.39 moles of (NH4)2SO4.

The maximum mass of ammonium sulphate that can be produced is calculated as follows:

m = n M = 20.41 mol 132 g/mol = 2694 g

The maximum amount.

The teacher further asked a question referring to example 9,

Why is it necessary to produce fertilisers? [Teacher].

For the production of good quality food. [G3L2].

How the necessary concepts of quantitative aspects of chemical change were clearly explained by the teacher with clarifications that industry productivity also depends on these critical aspects of change.

After the intervention post-test was administered, the post-test was identical to the pre-test. The results show that learners' performance in a post-test improved significantly when compared to the pre-test. The results are analysed and interpreted using a table and graph.

A close examination of the post-test reveals that the intervention process had a positive influence on the results. 60% of the learners achieved more than 50%, indicating that more learners understood the concept. Only 20% got less than 30%.

10% got between 30% and 40%.

### **11. Interviews**

Focus group interviews were conducted with 12 Grade 11 Physical Sciences learners for this study. Three groups of learners were formed. The category of these three formed by four learners in each were coded as (FL). The interviews were conducted to determine how well learners have gained new knowledge through collaborating with others when experiments were conducted. In the group of 50 learners, there was a mix of varying learner abilities from low to high achievers.

At the conclusion of the intervention, all learners took part in focus group interviews. The goal was to get their thoughts on how to implement the lesson. During interviews, learners were asked how they performed in the pre-test versus the posttest, as well as what motivated their responses. According to the responses, all of them scored higher on the post-test because of how the lesson was presented. They compared the lesson presentation to how it is usually taught. The following codes were obtained based on the responses of the learners: activities, experiments, learner participation, group activities, writing activities and approach preference (**Table 4**).

Learners reported that the experiments and demonstrations done in class were the main difference, as they had never done science experiments before. One learner stated that the way the teacher presented the lesson made them grasp all the


#### **Table 4.**

*Learners distribution in percentages indicating codes identified from data gathered.*

information, while the other stated that it was their first time doing experiments in class. All learners stated that they usually made notes, but this time, they wrote laboratory reports, which increased their knowledge retention. In terms of teacherlearner engagements, it was reported by learners that it was their norm to listen and form self-compiled notes, concurrently; for this lesson, there was maximum learner participation. Learners also shared that all learners engaged themselves in discussions as they were eager to see the experiment outcomes. This is supported by one learner who uttered: 'there was exchange of ideas throughout the discussions'.

As indicated by some learners, there were improved collaborations as learners were exposed to working with class members who never belonged to their groups. This has led to the formation of new friends and the extension of social skills. Another achieved skill, as perceived by learners, was compiling reports of what they observed, which was seen to have improved their writing capabilities.

Another learner indicated that they enjoyed writing by themselves. All of them preferred the way the researchers presented the lesson, citing reasons such as learning better, being motivated, enjoying the lesson, participation and involvement, and retention of new knowledge.

### **12. Discussion**

In this investigation, a conceptual change approach was administered to have a better understanding of quantitative aspects versus chemical change.

The study found that there was an improvement in learners' scientific understanding after pre-test and post-test. The study recommends a well-designed conceptual change instructional approach that leads to significantly better acquisition of scientific concepts. The study is significant because it addresses the issue of poor performance in Physical Sciences, particularly in the Eastern Cape Province of South Africa. The study suggests that a conceptual change instructional strategy is an effective teaching strategy that can be used to improve learners' understanding of science concepts. The study also highlights the importance of designing learning environments that allow learners to become aware of their current internal justifications and beliefs, which is essential for promoting conceptual change and improving problem-solving abilities. The study employed a qualitative research methodology, which is appropriate for exploring learners' misconceptions and difficulties on quantitative aspects of chemical change. The study used a case study approach and collected data from 50 learners and 12 teachers. The study used the Chemistry Achievement Test (CAT) to create lessons for the intervention programme and to determine the learners' alternate conceptions. The CAT examinations were piloted on a small sample of Grade 11 Physical Sciences teachers from neighbouring schools to confirm topic validity. The study's findings suggest that the conceptual change approach is an effective teaching

### *Implementation of Conceptual Change Approach to Improve Learners' Understanding… DOI: http://dx.doi.org/10.5772/intechopen.114094*

strategy that can be used to improve learners' understanding of science concepts. The study recommends a well-designed conceptual change instructional approach that leads to significantly better acquisition of scientific concepts. The study also highlights the importance of designing learning environments that allow learners to become aware of their current internal justifications and beliefs, which is essential for promoting conceptual change and improving problem-solving abilities. Overall, this study provides valuable insights into the use of conceptual change instructional strategy to improve learners' understanding of science concepts [14]. The study's findings have important implications for science education in South Africa and other countries facing similar challenges. The study suggests that science educators should consider using conceptual change instructional strategy to improve learners' understanding of science concepts and promote problem-solving abilities.

### **13. Findings**

The conceptual change approach was effective: The study found that the conceptual change approach was an effective teaching strategy that led to a significant improvement in learners' scientific understanding after pre-test and post-test. This means that learners who participated in the conceptual change instructional programme had a better understanding of the quantitative aspects of chemical change than those who did not participate in the programme.

Importance of designing learning environments: The study highlighted the importance of designing learning environments that allow learners to become aware of their current internal justifications and beliefs, which is essential for promoting conceptual change and improving problem-solving abilities. This means that teachers should create a classroom environment that encourages learners to reflect on their existing ideas and beliefs about a topic so that they can challenge and change them when necessary.

Qualitative research methodology: The study employed a qualitative research methodology, which is appropriate for exploring learners' misconceptions and difficulties on quantitative aspects of chemical change. This means that the study used open-ended questions and interviews to collect data on learners' understanding of the topic, rather than relying on standardised tests or surveys.

Case study approach: The study used a case study approach, which involved studying a particular group of learners or a specific classroom setting in depth. This allowed the researchers to get a detailed understanding of the learners' existing ideas and beliefs, as well as the effectiveness of the conceptual change instructional programme.

Use of Chemistry Achievement Test (CAT): The study used the Chemistry Achievement Test (CAT) to create lessons for the intervention programme and to determine the learners' alternate conceptions. The CAT examinations were piloted on a small sample of Grade 11 Physical Sciences teachers from neighbouring schools to confirm topic validity. This means that the study used a standardised test to assess learners' understanding of the topic and to create lessons that addressed their specific misconceptions.

Implications for science education: The study's findings have important implications for science education in South Africa and other countries facing similar challenges. The study suggests that science educators should consider using the conceptual change instructional strategy to improve learners' understanding of science concepts and promote problem-solving abilities. This means that science teachers

should incorporate a conceptual change approach into their teaching practice to help learners overcome their existing misconceptions and develop a deeper understanding of scientific concepts.

### **14. Conclusion**

In conclusion, this study provides valuable insights into the use of a conceptual change instructional strategy to improve learners' understanding of the quantitative aspects of chemical change. The study found that the conceptual change approach was an effective teaching strategy that led to a significant improvement in learners' scientific understanding after pre-test and post-test. The study also highlighted the importance of designing learning environments that allow learners to become aware of their current internal justifications and beliefs, which is essential for promoting conceptual change and improving problem-solving abilities.

The findings of the study have important implications for science education in South Africa and other countries facing similar challenges. Science educators should consider incorporating a conceptual change approach into their teaching practice to help learners overcome their existing misconceptions and develop a deeper understanding of scientific concepts. This approach has the potential to improve learners' academic performance and promote problem-solving abilities, which are critical skills for success in science and beyond. Overall, this study highlights the importance of adopting innovative teaching strategies that are grounded in educational research to promote effective learning and improve educational outcomes.

### **15. Recommendation**

Based on the findings of this study, there are several recommendations that can be made for science educators and policymakers. Firstly, science educators should consider incorporating a conceptual change approach into their teaching practice to help learners overcome their existing misconceptions and develop a deeper understanding of scientific concepts. This approach should be implemented in a well-designed learning environment that allows learners to reflect on their existing ideas and beliefs, which is essential for promoting conceptual change and improving problem-solving abilities. Secondly, policymakers should consider investing in teacher training and professional development programmes that focus on innovative teaching strategies that are grounded in educational research. These programmes can help to equip science teachers with the skills and knowledge they need to implement effective teaching strategies that promote conceptual change and improve educational outcomes. Lastly, further research should be conducted to explore the effectiveness of the conceptual change approach in other areas of science education and in other contexts. This can help to provide more evidence on the effectiveness of this approach and inform the development of more effective teaching strategies in science education.

*Implementation of Conceptual Change Approach to Improve Learners' Understanding… DOI: http://dx.doi.org/10.5772/intechopen.114094*
