Chemistry For Pedagogical Content Knowledge

Concepts of Chemistry

Discuss about the Chemistry for Pedagogical Content Knowledge.

Nowadays it has become a common problem that the instructors have to face in higher education that there is a lack of skill and prior knowledge among the students before enrolling in more advance curriculum and courses. It is not only a challenge for the students and the instructors but has become significant issue in curriculum design. Chemistry is the science of the matter (Osman and Sukor 2013). It looks very simple but in reality chemistry is a very broad and complex topic that represents a wide diversity of field. The composition, structure, properties and how the matter interacts or changes with energy are included in the chemistry of the matter (Yakmaci-Guzel, 2013 pp.95-104). There are different sub branches of chemistry present. These are inorganic chemistry, organic chemistry, analytical chemistry, physical chemistry, and biochemistry (Rowlinsonand Swinton2013).

The organic chemistry is the study of the compounds which contains carbon molecules that makes the living things and in the other hand the inorganic chemistry is the study of everything else (Espinosa et al. 2016 pp.104-124).

This branch of chemistry deals with the analysis of the chemical, the properties of the chemical and how they react. The analytical chemistry also includes the development of the methods and tools for performing the analytical work. Chemist of all disciplines uses analytical chemistry (Newman, 2013 pp.1655-1667).

Physical chemistry is the study of the physical principle of the atoms and compounds. It is nothing but the physics of the chemical compounds. It mainly examine how energy is involved in the reaction, how the particle moves, the speed at which the reaction occurs and the process in which the light and energy interact with matter (Bektas, 2015).

It is the branch of chemistry which deals with the study of the chemical processes that goes on inside the living things. This study includes the reaction occurring between the large biological molecules like the protein, lipid, carbohydrate, and DNA (Ince et al. 2012 pp.993-1004).

Chemistry is a subject that is concerned with the properties and reaction of the substances. The students operatesand live in the macroscopic world of the matter. They doesn’t encounter what aggregation of particle forms the substances, what is the nature of the bonding between those particles and what are the chemical properties of the substances (Speight, 2014). The student fail to understand the shift between this macroscopic and microscopic levels. So it becomes very difficult to make them understand the chemical phenomena that is taking place. The list of thing where there is possibilities of occurrence of misconception is possible includes misconception or wrong interpretation in Mole concept,Number of Mole, Balancing Equations, Graphing, oxygen carbon ratio, concept of peptides bond, theory of spectroscopy and in the understanding of the oxidation reduction reactions (Smithand Villarreal2015).

Organic and Inorganic Chemistry

It is important to have a clear concept in the study of chemistry, which will help the students to apply the concepts in practice. Nevertheless, in cases the students are unable to answer the practical based questions of chemistry due to the lack of clear concept. In the assessment report of 2011 to 2015 it is clear that the students lack the concept related to the acid-base chemistry.

In the question 11 of paper of 2011, the student has not understood the concept of equivalence point and hence is not able to give the correct answer related to the titration. The idea of weak and strong acid is not clear and is unable to apply the concept in practice. In the question 8 of 2012 also the student has failed to apply the concept of titration in practical work. The techniques that are used in the titration are related to the concept of acid and base and hence it is the student has failed to use the correct concept.

The question 2 of the 2013 paper is related to the concept of weak and strong acid. It is also important to use the idea of acid-base indicator for this question. Moreover, in question 3 it is important to use the concept of weak and strong acid base in doing the work of titration. The student has also failed to detect the area, where the experiment of titration went wrong. On the other hand, it is important to have the concept of pH, which is the parameter to measure the strength of an acid or base. In order to answer the questions of 19 and 20 it is essential for the student to differentiate the understanding of concentration and strength of the acid.           

In the paper of 2014, the student has failed to use the concept of weak acid and strong acid in the answering question 30. Moreover, the student has unable to balance the reaction of that requires the idea about the molar concept and the chemical formulae of the acid. The concept of nomenclature of the acid and base is also essential. It also crucial to have the concepts related to organic and inorganic acid, which will help the student to answer the questions that are related to organic chemistry.

In the assessment report of the paper of 2015 it is clear that the student has failed to understand the connection of the concept of equilibrium and weak acids in answering question 8. The part c of the question needs to have the concept of Le Chaterliers’s principle.

Analytical Chemistry

The teaching plan that need to be implemented to have clear concept of acid base chemistry need to be divided into three different stages:

1) Learning based on the activity and having a quality style of education

2) Planning of the daily activity based on the spirit of learning based activity

3) The concepts related to the acid-base chemistry need to be localized and the role of the acid base chemistry in daily life need to be appreciated.   

The acids and bases are one of the most widely used chemicals in the everyday life and it will help the students to relate the study of acid-base chemistry. At the beginning it is important to understand the concept of nomenclature and chemical formulae of the acid and base related compounds. Then the student must understand the idea of radicals that is related to the acid and base. The H⁺ ion determines the concentration of acid and on the other hand the OH^- is the indicator for the concentration of base in a medium. Every chemical solution can be divided into acidic, basic or neutral solution. It is important to have the concept of pH, which is the most important parameter to determine whether a sample is acidic, basic or neutral in nature. The pH meter is also able to determine the strength of acid and base of a solution. There is a scale of 0-14 that is marked in the pH meter. The substances that are having the pH of less than 7 are considered to be acidic in nature and those which have a pH of higher than 7 is considered to be basic in nature. On the other hand the substance, which has pH of exact 7, is considered to be neutral. The litmus paper is used to determine the pH of a substance. If the colour the litmus paper turns to red it is an acidic solution and the blue colour will indicate that the solution is basic in nature.

In mathematical term pH can be defined as the reciprocal of concentration of the hydrogen ion activity converted in terms of logarithmic scale with base ten.

pH= -log₁₀ (a_H+) . Where a_H+ is the activity of the hydrogen ion.    

The teacher also needs to teach the concept of weak and strong acid along with the concept of organic and inorganic acid. The fatty acid that is present in the human body is one of the most important forms of organic acid that is present within the human body. It is also an important constituent of the cell membrane of animals.

Physical Chemistry

The concept of ionization is important to understand the difference of the weak acid and strong acid. Moreover, the idea related to the chemical equilibrium is a vital part for understanding of the acid base concept.  

The teacher can use the digital technology to help the students understand the concept of acid base chemistry. The visual figures explaining the chemical formulae of the acid and base will help the student understand the difference in the acid, base and salt (Lee, 2015 166, pp.616-622). The teacher can also take the help of common acids and base that are used in everyday life, which will assist the students to relate the theoretical concepts of acid and base with the practical use. The teacher will also arrange for simple practical experiment that will help the student to grow their interest in the study of acid base chemistry. The teacher can also take the help of the fruits and vegetables, where the organic acid is present. Like the citric acid that is present in the lemon is one of the essential forms of organic acid. The student also needs to understand the role of these organic acids in the health of human body.

Reference

Bektas, O., 2015. Pre-Service Science Teachers’ Pedagogical Content Knowledge in The Physics, Chemistry, and Biology Topics. European Journal of Physics Education, 6(2).

Espinosa, A.A., España, R.C.N. and Marasigan, A.C., 2016. Investigating Pre-service Chemistry Teachers’ Problem Solving Strategies: Towards Developing a Framework in Teaching Stoichiometry. Journal of Education in Science, Environment and Health, 2(2), pp.104-124.

Ince, E., Sesen, B.A. and Kirbaslar, F.G., 2012. Investigation of undergraduate students' understanding of radiation and radioactivity. Energy Education Science and Technology Part B-Social and Educational Studies, 4(2), pp.993-1004.

Lee, J., 2015. Sorbitol, Rubus fruit, and misconception. Food chemistry, 166, pp.616-622.

Newman, M., 2013. Emergence, supervenience, and introductory chemical education. Science & Education, 22(7), pp.1655-1667.

Osman, K. and Sukor, N.S., 2013. Conceptual understanding in secondary school chemistry: A discussion of the difficulties Experienced by students. American Journal of Applied Sciences, 10(5), p.433.

Rowlinson, J.S. and Swinton, F., 2013. Liquids and Liquid Mixtures: Butterworths Monographs in Chemistry. Butterworth-Heinemann.

Smith, K.C. and Villarreal, S., 2015. A reply to “Reinterpretation of Students' Ideas when Reasoning about Particle Model Illustrations. A Response to “Using Animations in Identifying General Chemistry Students' Misconceptions and Evaluating their Knowledge Transfer Relating to Particle Position in Physical Changes” by Smith and Villarreal (2015)”. Chemistry Education Research and Practice, 16(3), pp.701-703.

Speight, J.G., 2014. The chemistry and technology of petroleum. CRC press.

Yakmaci-Guzel, B., 2013. Preservice chemistry teachers in action: an evaluation of attempts for changing high school students' chemistry misconceptions into more scientific conceptions. Chemistry Education Research and Practice, 14(1), pp.95-104.