OVERVIEW
Chemistry is a key science in explaining the workings of our universe through an understanding of the properties and interaction of substances that make up matter. A knowledge of chemistry gives an understanding of a broad range of human activities including medicine, domestic science, industrial development, use of machines and scientific research. As such, chemistry is a prerequisite or recommended subject for a large number of tertiary courses. However, students should be encouraged to study this subject not simply because they must, rather, it provides a chance to understand more about the materials we encounter in everyday life.
CONTENT
UNIT 1: HOW CAN THE DIVERSITY OF MATERIALS BE EXPLAINED?
AREAS OF STUDY
How Can Knowledge Of Elements Explain The Properties Of Matter?
In this area of study, students focus on the nature of chemical elements, their atomic structure and their place in the periodic table. They review how the model of the atom has changed over time, consider how spectral evidence led to the Bohr model and, subsequently, to the Schrödinger model. Students examine the periodic table as a unifying framework into which elements are placed based upon similarities in their electronic configurations. In this context, students explore patterns, trends of and relationships between elements, with reference to properties of the elements, including their chemical reactivity.
Students investigate the nature of metals and their properties, including metallic nanomaterials. They investigate how a metal is extracted from its ore and how the properties of metals may be modified for a particular use. Students apply their knowledge of the electronic structures of metallic elements and non-metallic elements to examine ionic compounds. They study how ionic compounds are formed, explore their crystalline structures and investigate how changing environmental conditions may change their properties.
Fundamental quantitative aspects of chemistry are introduced including the mole concept, relative atomic mass, percentage abundance, composition by mass and empirical formula.
How Can The Versatility Of Non-Metals Be Explained?
In this area of study students explore a wide range of substances and materials made from non-metals including molecular substances, covalent lattices, carbon nanomaterials, organic compounds and polymers.
Students investigate the relationship between the electronic configurations of non-metallic atoms, the resultant structures and the properties of a range of molecular substances and covalent lattices. They compare how the structures of these non-metallic substances are represented and analyse the limitations of these representations.
Students study a variety of organic compounds and how they are grouped into distinct chemical families. They apply rules of systematic nomenclature to each of these chemical families. Students investigate useful materials that are made from non-metals and relate their properties and uses to their structures. They explore the modification of polymers and the use of carbon-based nanoparticles for specific applications.
Students apply quantitative concepts to molecular compounds, including the mole concept, percentage composition by mass and empirical and molecular formulas of given compounds.
Research Investigation
Knowledge of the origin, structure and properties of matter has built up over time through scientific and technological research, including medical research, space research and research into alternative energy resources. As a result, patterns and relationships in structures and properties of substances have been identified, applied and modified, and a vast range of useful materials and chemicals has been produced. This research and development is ongoing and new discoveries are being made at an accelerating rate.
In this area of study, students apply and extend their knowledge and skills developed in Area of Study 1 and Area of Study 2 to investigate a selected question related to materials. They apply critical and creative thinking skills, science inquiry skills and communication skills to conduct and present the findings of an independent investigation into one aspect of the discoveries and research that have underpinned the development, use and modification of useful materials or chemicals.
For the selected question, students outline, analyse and evaluate relevant evidence to support their conclusions.
UNIT 2: WHAT MAKES WATER SUCH A UNIQUE CHEMICAL?
AREAS OF STUDY
How Do Substances Interact With Water?
In this area of study, students focus on the properties of water and the reactions that take place in water including acid-base and redox reactions. Students relate the properties of water to the water molecule’s structure, polarity and bonding abilities. They also explore the significance of water’s high specific heat capacity and latent heat of vaporisation for living systems and water supplies. Students investigate issues associated with the solubility of substances in water. Precipitation, acid-base and redox reactions that occur in water are explored and represented by the writing of balanced equations. Students compare acids with bases and learn to distinguish between acid strength and acid concentration. The pH scale is examined and students calculate the expected pH of strong acids and strong bases of known concentration.
How Are Substances In Water Measured And Analysed?
In this area of study students focus on the use of analytical techniques, both in the laboratory and in the field. These are used to measure the solubility and concentrations of solutes in water and to analyse water samples for various solutes including chemical contaminants.
Students examine the origin and chemical nature of substances that may be present in a water supply, including contaminants, and outline sampling techniques used to assess water quality. They measure the solubility of substances in water, explore the relationship between solubility and temperature using solubility curves and learn to predict when a solute will dissolve or crystallise out of solution.
The concept of molarity is introduced and students measure concentrations of solutions using a variety of commonly used units. Students apply the principles of stoichiometry to gravimetric and volumetric analyses of aqueous solutions and water samples. Instrumental techniques include the use of colorimetry and/or UV-visible spectroscopy to estimate the concentrations of coloured species in solution, atomic absorption spectroscopy data to determine the concentration of metal ions in solution and high performance liquid chromatography data to calculate the concentration of organic compounds in solution.
Practical Investigation
Substances that are dissolved in water supplies may be beneficial or harmful, and sometimes toxic, to humans and other living organisms. They may also form coatings on, or corrode, water pipes. In this area of study students design and conduct a practical investigation into an aspect of water quality. The investigation relates to knowledge and skills developed in Area of Study 1 and Area of Study 2 and is conducted by the student through laboratory work and/or fieldwork.
The investigation requires the student to develop a question, plan a course of action that attempts to answer the question, undertake an investigation to collect the appropriate primary qualitative and/or quantitative data (which may including collecting water samples), organise and interpret the data and reach a conclusion in response to the question.
UNIT 3: HOW CAN CHEMICAL PROCESSES BE DESIGNED TO OPTIMISE EFFICIENCY?
AREAS OF STUDY
What Are The Options For Energy Production?
In this area of study students focus on analysing and comparing a range of energy resources and technologies, including fossil fuels, biofuels, energy efficiencies, environmental impacts and potential applications, galvanic cells and fuel cells, with reference to the energy transformations and chemical reactions involved. Students use the specific heat capacity of water and thermochemical equations to determine the enthalpy changes and quantities of reactants and products involved in the combustion reactions of a range of renewable and non-renewable fuels.
Students conduct practical investigations involving redox reactions, including the design, construction and testing of galvanic cells, and account for differences between experimental findings and predictions made by using the electrochemical series. They compare the design features, operating principles and uses of galvanic cells and fuel cells, and summarise cell processes by writing balanced equations for half and overall cell processes.
How Can The Yield Of A Chemical Product Be Optimised?
In this area of study students explore the factors that increase the efficiency and percentage yield of a chemical manufacturing process while reducing the energy demand and associated costs.
Students investigate how the rate of a reaction can be controlled so that it occurs at the optimum rate while avoiding unwanted side reactions and by-products. They explain reactions with reference to the collision theory including reference to Maxwell-Boltzmann distribution curves. The progression of exothermic and endothermic reactions, including the use of a catalyst, is represented using energy profile diagrams.
Students explore homogeneous equilibrium systems and apply the equilibrium law to calculate equilibrium constants and concentrations of reactants and products. They investigate Le Chatelier’s principle, the effect of different changes on an equilibrium system and make predictions about the optimum conditions for the production of chemicals, taking into account rate and yield considerations. Students represent the establishment of equilibrium and the effect of changes to an equilibrium system using concentration-time graphs.
Students investigate a range of electrolytic cells with reference to their basic design features, purpose, operating principles and energy transformations that occur. They examine the discharging and recharging processes in rechargeable cells and apply Faraday’s laws to calculate quantities in electrochemistry and to determine cell efficiencies.
UNIT 4: HOW ARE ORGANIC COMPOUNDS CATEGORISED, ANALYSED AND USED
AREAS OF STUDY
How Can The Diversity Of Carbon Compounds Be Explained And Categorised?
In this area of study students explore why such a vast range of carbon compounds is possible. They examine the structural features of members of several homologous series of compounds, including some of the simpler structural isomers, and learn how they are represented and named.
Students investigate trends in the physical and chemical properties of various organic families of compounds. They study typical reactions of organic families and some of their reaction pathways, and write balanced chemical equations for organic syntheses.
Students learn to deduce and confirm the structure and identity of organic compounds by interpreting data from mass spectrometry, infrared spectroscopy and proton and carbon-13 nuclear magnetic resonance spectroscopy.
What Is The Chemistry Of Food?
Food contains various organic compounds that are the source of both the energy and the raw materials that the human body needs for growth and repair. In this area of study, students explore the importance of food from a chemical perspective.
Students also study the major components of food with reference to their structures, properties and functions. They examine the hydrolysis reactions in which foods are broken down, the condensation reactions in which new biomolecules are formed and the role of enzymes, assisted by coenzymes, in the metabolism of food.
Students study the role of glucose in cellular respiration and investigate the principles of calorimetry and its application in determining enthalpy changes for reactions in solution. They explore applications of food chemistry by considering the differences in structures of natural and artificial sweeteners, the chemical significance of the glycaemic index of foods, the rancidity of fats and oils and the use of the term ‘essential’ to describe some amino acids and fatty acids in the diet.
Practical Investigation
A student-designed or adapted practical investigation related to energy and/or food is undertaken in either Unit 3 or Unit 4, or across both Units 3 and 4. The investigation relates to knowledge and skills developed across Unit 3 and/or Unit 4.
The investigation requires the student to identify a purpose, develop a question, formulate a hypothesis and plan a course of action to answer the question and that complies with safety and ethical requirements. The student then undertakes an experiment that involves the collection of primary qualitative and/or quantitative data, analyses and evaluates the data, identifies limitations of data and methods, links experimental results to science ideas, reaches a conclusion in response to the question and suggests further investigations which may be undertaken. Findings are communicated in a scientific poster format. A practical logbook must be maintained by the student for record, authentication and assessment purposes.
BIBLICAL PERSPECTIVE
Many topical issues are explored in the units of study, allowing opportunities to discuss these from a Christian viewpoint. The Psalmist reminds us that “the earth is the Lord’s and everything in it” (Ps 24:1), but at creation God gave man a position of authority under His authority. As His stewards of the earth, we need to treat its chemical resources responsibly. It is important that we show concern for our “neighbour” - the present and future generations that may be affected by waste disposal - and for the treatment of the environment and the excessive use or misuse of materials. Through understanding the chemical principles involved in God’s Creation, students of Chemistry become equipped to produce, modify and analyse substances encountered in everyday life.
The group and discussion work purposes to foster cooperation and mutual respect between students.
It is hoped that increased understanding of the complexity and the order of the materials that make up our physical world will inspire wonder at the creation and appreciation of our mighty Creator.
ASSESSMENT
UNIT 1
For this unit students are required to demonstrate achievement of three outcomes. As a set, these outcomes encompass all areas of study. Suitable tasks for assessment may be selected from the following:
For Outcomes 1 and 2 from a range of:
For Outcome 3
UNIT 2
For this unit students are required to demonstrate achievement of three outcomes. As a set, these outcomes encompass all areas of study.
Suitable tasks for assessment may be selected from the following:
For Outcomes 1 and 2
For Outcome 3
UNIT 3
UNIT 4
EXTERNAL ASSESSMENT
The level of achievement for Units 3 and 4 is also assessed by an end-of-year examination. The examination will contribute to 60%.