chemistry-timeline Unit 4

Timeline VCE

Chemistry Unit 2 (2023-2026)

Unit 2: How do chemical reactions shape the natural world?

Society is dependent on the work of chemists to analyse the materials and products in everyday use. In this unit students analyse and compare different substances dissolved in water and the gases that may be produced in chemical reactions. They explore applications of acid-base and redox reactions in society. Students conduct practical investigations involving the specific heat capacity of water, acid-base and redox reactions, solubility, molar volume of a gas, volumetric analysis, and the use of a calibration curve.

Throughout the unit students use chemistry terminology, including symbols, formulas, chemical nomenclature and equations, to represent and explain observations and data from their own investigations and to evaluate the chemistry-based claims of others.
A student-adapted or student-designed scientific investigation is undertaken in Area of Study 3. The investigation involves the generation of primary data and is related to the production of gases, acid-base or redox reactions, or the analysis of substances in water. It draws on the key science skills and key knowledge from Unit 2 Area of Study 1 and/or Area of Study 2.

Area of Study 1
How do chemicals interact with water
In this area of study students focus on understanding the properties of water and investigating acid-base and redox reactions. They explore water’s properties, including its density, specific heat capacity and latent heat of vaporisation. They write equations for acid-base and redox reactions, and apply concepts including pH as a measure of acidity. They explore applications of acid-base reactions and redox reactions in society.

The selection of learning contexts should allow students to develop practical techniques to investigate the properties of water and acid-base and redox reactions. Students develop their skills in the use of scientific equipment and apparatus. They may demonstrate their understanding of concentration using coloured solutions such as ammonium molybdate. Students explore pH: for example, by making their own indicators from natural materials, developing their own pH scale and comparing the accuracy of their indicators with commercial indicators. They may investigate redox reactions by comparing corrosion rates of iron in tap water and sea water or building simple cells to power a diode. They respond to challenges such as investigating the action of soda water on seashells and linking their findings to socio-scientific issues such as ocean acidification

Outcome 1
On completion of this unit the student should be able to explain the properties of water in terms of structure and bonding, and experimentally investigate and analyse applications of acid-base and redox reactions in society.
To achieve this outcome the student will draw on key knowledge outlined in Area of Study 1 and the related key science skills on pages 11 and 12 of the study design.

Week	key knowledge	Topics and Lessons	Resources/Activities (activities listed in no particular order)

	Water as a unique chemical • the existence of water in all three states at Earth’s surface, including the distribution and proportion of available drinking water • the relatively high latent heat of vaporisation of water and its impact on the regulation of the temperature of the oceans and aquatic life Lesson 1a Solutions - covers water as a regulator of temperature and climate and its impact on aquatic ecosystems as well as the distribution of drinking water. • explanation of the anomalous properties of H₂O (ice and water), with reference to hydrogen bonding: - trends in the boiling points of Group 16 hydrides - the density of solid ice compared with liquid water at low temperatures - specific heat capacity of water including units and symbols Lesson 1b - Trends in MP of hydrides Lesson 2 - hydrogen bonding Lesson 3 - Heat capacity Lesson 4 - Latent heat	Quiz 1 Solutions - trends in hydrides Quiz 1a Solutions - Specific heat Quiz 2 Solutions - latent heat Quiz 3 Solutions - latent heat Quiz 4 Solutions - latent heat Quiz 5 Solutions - specific heat capacity, heat capacity.
	Acid-base (proton transfer) reactions in water • the Brønsted-Lowry theory of acids and bases, including polyprotic acids and amphiprotic species, and the writing of balanced ionic and full equations, with states, for their reactions in water Lesson 1 - Video worksheet -definitions and terminology used in acid/base. lesson 1a- conjugates Lesson 2 - dilution • the ionic product of water, the pH scale and the use of pH in the measurement and calculations of strengths of acids and bases and dilutions of solutions (calculations involving acidity constants are not required) Lesson 3 (pdf) Lesson 3(doc)- Solutions Lesson 3a - pH Lesson 3b - pH calculations - Video worksheet • the distinction between strong and weak acids and strong and weak bases, and between concentrated and dilute acids and bases, including common examples Lesson 4 Solutions - Strong/weak acids Lesson 4a - Video worksheet • the reactions of acids with metals, carbonates and hydroxides including balanced full and ionic equations, with states Lesson 5 - reactions with acids, some reactions covered are beyond the scope of the course Lesson 5a - Video worksheet Lesson 6 - ionic equations for acid reactions Lesson 6a - ionic equations for salts - video worksheet • neutralisation reactions to produce salts: - reactions of acids with metal carbonates and hydroxides, including balanced full and ionic equations, with states - types of antacids and their use in the neutralisation of stomach acid Lesson 7 - Video worksheet covering salts produced during neutralisation reactions taking place when antacids are ingested. • accuracy and precision in measurement as illustrated by the comparison of natural indicators, commercial indicators, and pH meters to determine the relative strengths of acidic and basic solutions Lesson 8 - Video worksheet on indicators and instrument resolution. • applications of acid-base reactions in society: for example, natural acidity of rain due to dissolved CO₂ and the distinction between the natural acidity of rain and acid rain, or the action of CO₂ forming a weak acid in oceans and the consequences for shell growth in marine invertebrates Lesson 9 Solution - Worksheet acid rain covering reactions between acidic gases and water as well acid reactions between metal carbonates, metal hydroxides and metal sulfides.	Quiz 1 Solutions - overall acid equations and ionic equations Quiz 2 Solutions - pH, [H₃O⁺], [OH^-] , conjugates, 10^-14 = [H₃O⁺][OH^-], strong/weak acid, Antacid activity - Measuring the concentration of the acitive ingredient of an antacid tablet. This is to be found towards the end of the video on acids.bases.
	Redox (electron transfer) reactions oxidising and reducing agents, and redox reactions, including writing of balanced half and overall redox equations (including in acidic conditions), with states Lesson 1 - introduction to redox reactions. Lesson 2 Worksheet 2 Solutions - oxidation numbers Lesson 3a Solution - half reactions, identifying oxidation and reduction reactions Lesson 3b - writing of blanced half equations in acidic solutions Lesson 4 Solution - half equations to balanced overall equation the reactivity series of metals and metal displacement reactions, including balanced redox equations, with states Lesson 5 - the electrochemical series to predict spontaneous redox reactions and reactivity of metals. applications of redox reactions in society: for example, corrosion or the use of simple primary cells in the production of electrical energy from chemical energy Lesson 6 - the electrochemical series as a tool. Lesson 7 - metal displacement reactions Lesson 8 - overall equations to half equations Lesson 9 - from overall equation to galvanic cell design. Worksheet Solutions - This worksheet includes, redox reactions in everyday life, from metal displacment, to energy source and purification of water. It is recommended that teachers use this as a revision tool rahter htan an assessment, alhtough this is up to the teacher. Summary	Reactivity of metal using a lemon battery Experiment "Rusting of metals" Experiment "Reactivity of metals" Experiment - developing an E^o series Quiz 1 Solutions - introduction Quiz 2 Solutions - writing balanced redox half equations and overall equations. Quiz 3 Solutions- Identifying the oxidant and reductant using oxidation numbers and deriving oxidation and reduction half-equations. Quiz 4 Solutions - drawing galvanic cells from an overall redox reaction Quiz 5 Solutions- identifying redox reactions through oxidation numbers. Quiz 6 Solutions - revision
	Area of Study 2 How are chemicals measured and analysed? In this area of study students focus on the analysis and quantification of chemical reactions involving acids, bases, salts and gases. 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. They quantify amounts in chemistry using volumetric analysis, application of the ideal gas equation, stoichiometry and calibration curves. The selection of learning contexts should allow students to develop practical techniques to investigate substances that may be dissolved in water or found in soils, particularly salts, acids and bases, as well as gases. Students develop their skills in the use of scientific equipment and apparatus. They use precipitation reactions to purify water: for example, by using iron or aluminium compounds to precipitate and remove phosphorus from wastewater. They perform acid-base titrations, such as comparing the ethanoic acid concentrations of vinegar, mayonnaise and tomato sauce. They construct calibration curves to analyse unknown concentrations of substances, such as the amount of nitrates or phosphates in water or soil samples. Students respond to challenges such as determining the set of standards required in setting up a calibration curve in colorimetry.
	Outcome 2 On completion of this unit the student should be able to calculate solution concentrations and predict solubilities, use volumetric analysis and instrumental techniques to analyse for acids, bases and salts, and apply stoichiometry to calculate chemical quantities. To achieve this outcome the student will draw on key knowledge outlined in Area of Study 2 and the related key science skills on pages 11 and 12 of the study design.
	Key knowledge Measuring solubility and concentration solution concentration as a measure of the quantity of solute dissolved in a given mass or volume of solution (mol L^-, g L^-, %(m/v), %(v/v), ppm), including unit conversions Lesson 1 - Videoworksheet on concetrations such as %m/m, %v/v, ppm and molarity. As well as conversion between different concentration units. Lesson 1a Solutions - continuation of Lesson 1 (concentration units) -ppm -(v/v)% -(w/v)% -(w/w)% Lesson - Molarity the use of solubility tables and solubility graphs to predict experimental determination of ionic compound solubility; the effect of temperature on the solubility of a given solid, liquid or gas in water Lesson 2 - working with solubility curves the use of precipitation reactions to remove impurities from water Lesson 3 - Writing precipitation reactions i(includes a link to a videoworksheet)	Quiz 1 Solutions (precipitates overall equations and ionic equations) Quiz 2 Solutions ( overall equations and ionic equations) Quiz 1 Solutions concentrations %w/w,%w/v, %v/v, molarity, ppm. Quiz 2a Solutions concentrations of ions Quiz 2b Solutions calculating amount of solute Concentration (ppm, %v/v, %w//v, %w/w) revision sheet solution Quiz 3 Quiz 4 Solutions -more precipitation reactions overall and ionic equation Revision 1 Solutions Practical activity Solutions Constructing a solubility curve for KNO₃ Practical- Determination of Sulphate content in fertiliser Precipitation activity(1) Precipitation activity.(2) Solubility curve of KNO₃ Solutions practical investigation.
	Analysis for acids and bases volume-volume stoichiometry (solutions only) and application of volumetric analysis, including the use of indicators, calculations related to the preparation of standard solutions, dilution of solutions, and use of acid-base titrations (excluding back titrations) to determine the concentration of an acid or a base in a water sample Lesson 1- Video worksheet involving volumetric analysis involving stoichiometry, dilution and indicators as well as errors. Lesson 2 Solutions vol -vol stoichiometry -introduction to volumetric analysis Lesson 2a - Titration and the glassware Lesson 3 - indicators,equivalence point, end point and pH curves Lesson 3a Solution- indicators Lesson 3b Solution - dilution and titration Lesson 3c Solution - dilution and titration Lesson 3d Solution - dilution, titration and indicators Lesson 4 Solution - dilution and titration Lesson 4a Solution - dilution and titration Lesson 5 - standard solutions, primary standard Lesson5a Solution - standard solution and titration Lesson 6 Solution - errors and indicators in titration Lesson 7 - virtual analysis of acetylsalicylic acid in an aspirin tablet. Volumetric analysis summary sheet.	Quiz 1 Solution - pH Quiz 2 Solution - excess calculation and pH Quiz 3 Solution Quiz 4 Solution Quiz 5 Solution Quiz 6 Solution Quiz 7 Solution
	Measuring gases CO₂, CH₄ and H₂O as three of the major gases that contribute to the natural and enhanced greenhouse effects due to their ability to absorb infrared radiation Lesson 1 - Different greenhouse gases and the way heat energy is trapoped in the atmosphere. the definitions of gas pressure and standard laboratory conditions (SLC) at 25 °C and 100 kPa calculations using the ideal gas equation (pV = nRT), limited to the units kPa, Pa, atm, mL, L ,°C, and K (including unit conversions) Lesson 2 - Videoworksheet on using and manipulating the ideal gas formula (PV=nRT) to undertake a variety of calculations. the use of stoichiometry to solve calculations related to chemical reactions involving gases (including moles, mass and volume of gases Lesson 3 Solutions - this worksheet continues on from lesson 4 dealing with PV=nRT and stoichiometric calculations involving gases in chemical reactions as well as green house gases and the mechanism by which they absorb radiation. calculations of the molar volume or molar mass of a gas produced by a chemical reaction Lesson 4 - activity to calculate, experimentally, the molar mass of CO₂ gas	Practical activity to experimentally determine the molar mass of CO₂
	Analysis for salts sources of salts found in water or soil (which may include minerals, heavy metals, organo-metallic substances) and the use of electrical conductivity to assess the salinity and quality of water or soil samples Lesson 1 Solutions - Investigation to examine the relationship between salt concentration and current by constructing a calibration curve. quantitative analysis of salts: - molar ratio of water of hydration for an ionic compound Lesson 2 - empirical formula of a hydrated salt CuSO₄.XH₂O(practrical activity) - the application of mass-mass stoichiometry to determine the mass present of an ionic compound Lesson 3 - gravimetric analysis of carbonates (practical activity) - the application of colorimetry and/or UV-visible spectroscopy, including the use of a calibration curve to determine the concentration of ions or complexes in a water or soil sample Lesson 4 -UV-Visible spectroscopy Lesson 5 -Introduction to colorimetry and calibration curves for solution analysis	Gravimetric analysis Sulphate content in fertiliser Experimentally determining the degree of hydration of CUSO₄ Selection of Friday quizzes. The teacher can decide when to use these quizzes to gauge student progress. Quiz 1 Solution Quiz 2 Solution Quiz 3 Solution Quiz 4 Solution Quiz 5 Solution Quiz 6 Solution Revision for gravimetric analysis (1) Solution Revision for gravimetric analysis (2) Solution Revision for gravimetric analysis (3) Solution UV-visible Quiz 1 Solution Quiz 2 Solution Quiz 3 Solution Quiz 4 Solution Quiz 5 Solution	Gravimetric analysis from past exams. 2014 VCE 2013 VCE 2012 VCE 2011 VCE 2010 VCE 2010 HSC 2009 VCE 2008 VCE 2007 VCE 2007 NSW 2006 VCE 2005 VCE

	Outcome 3 On completion of this unit the student should be able to design and undertake a quantitative laboratory investigation related to water quality, and draw conclusions based on evidence from collected data. To achieve this outcome the student will draw on key knowledge outlined in Area of Study 3 and the related key science skills on pages 10 and 11 of the study design. Key knowledge • the chemical concepts specific to the investigation and their significance, including definitions of key terms, and chemical representations • the characteristics of laboratory techniques of primary qualitative and quantitative data collection relevant to the investigation: sampling protocols; gravimetric analysis, acid-base titrations and/or pH measurement; precision, accuracy, reliability and validity of data; and minimisation of experimental bias • ethics of and concerns with research including identification and application of relevant health and safety guidelines • methods of organising, analysing and evaluating primary data to identify patterns and relationships including identification of sources of error and uncertainty, and of limitations of data and methodologies • observations and experiments that are consistent with, or challenge, current chemical models or theories • the nature of evidence that supports or refutes a hypothesis, model or theory • options, strategies or solutions to issues related to water quality • the key findings of the selected investigation and their relationship to solubility, concentration, acid/base and/ or redox concepts • the conventions of scientific report writing including chemical terminology and representations, symbols, chemical equations, formulas, units of measurement, significant figures and standard abbreviations.
	Assessment The award of satisfactory completion for a unit is based on a decision that the student has demonstrated the set of outcomes specified for the unit. Teachers should use a variety of learning activities and assessment tasks that provide a range of opportunities for students to demonstrate the key knowledge and key skills in the outcomes. The areas of study, including the key knowledge and key skills listed for the outcomes, should be used for course design and the development of learning activities and assessment tasks. Assessment must be a part of the regular teaching and learning program and should be completed mainly in class and within a limited timeframe.
Revision Unit 2 2012 Solutions