Unit 3: Chemical Pathways

Prerequisites

Students are advised to complete Chemistry Units 1 and 2 before undertaking Unit 3 Chemistry. Mathematical Methods is strongly recommended.

Scope of the unit

In this unit students investigate the scope of techniques available to the analytical chemist. Chemical analysis is vital in the work of the forensic scientist, the quality control chemist at a food manufacturing plant, the geologist in the field, and the environmental chemist monitoring the health of a waterway.

Each technique of analysis depends on a particular property or reaction of the chemical being investigated. Consequently, an understanding of the chemistry is necessary in learning how and why the techniques work. Some techniques of analysis have been refined over many years to make them quicker and more accurate. Other techniques are now used in combination to provide higher and more reliable levels of accuracy, for example gas chromatography and mass spectrometry, or carbon-13 and proton nuclear magnetic resonance spectroscopy.

Students investigate organic reaction pathways and the chemistry of particular organic molecules. A detailed knowledge of the structure and bonding of organic chemicals is important to the work of the synthetic organic chemist. In the wake of the work done on the genome project, synthesis of new
medicines is one of the growth industries for the coming decades. Students investigate the role of organic molecules in the generation of biochemical fuels and forensic analysis.

Areas of study

Chemical Analysis
In this area of study students use a variety of analytical techniques to analyse products in the laboratory. They conduct volumetric analyses using acid-base and redox titrations and standard solutions, and carry out gravimetric analyses. They are also introduced to instrumental analytical techniques of spectroscopy and chromatography. Students review and apply their understanding of stoichiometry as they complete calculations related to their practical investigations. Students relate the operation of the analytical techniques and instruments to the chemical reactions and the chemical structures of the materials which are being analysed.

Organic Chemical Pathways
In this area of study students investigate systematic organic chemistry including production of starting materials for particular reaction pathways. Students use molecular models and conduct simple laboratory investigations to observe the properties and reactions of different homologous series and functional groups. Students investigate the use of biochemical fuels. They design reaction pathways to prepare organic compounds from given starting materials. Students investigate how forensic analysis relies on the use of organic chemicals and the role of organic chemicals in the development of medicines.

Assessment

Outcomes	Assessment Tasks (School-assessed Coursework)	Marks Allocated
Students will have satisfactorily completed this unit when they have demonstrated the specific set of outcomes listed below:
Evaluate the suitability of techniques and instruments used in chemical analysis.	An extended experimental investigation that can be drawn from either Area of Study 1 or Area of Study 2.	50
Identify and explain the role of functional groups in organic reactions and construct reaction pathways using organic molecules.	From the area of study NOT used for the extended experimental investigation – A written report of one practical activity. AND One task selected from the following: a response to stimulus material in written, oral or visual format an analysis of first or second-hand data using structured questions a report in written, oral, multimedia or visual format.	25     25
Total Marks		100

Note: These Assessment Tasks may change in response to changes to the Chemistry study design made by the Victorian Curriculum and Assessment Authority. School-assessed Coursework for Unit 3 will contribute 20% to the final assessment.

Examination
In addition to the Assessment Tasks, students will be required to sit an end-of-year examination of 2½ hours which contributes 60% to the final assessment.

Reproduced by permission of the Victorian Curriculum and Assessment Authority, Victoria, Australia. Web Address www.vcaa.vic.edu.au