Central Syllabus Outcome:
In our bodies, in our homes, and in our industrial society, acids and bases play key roles. Proteins, enzymes, blood, genetic material, and other components of living matter contain both acids and bases. We seem to like the sour taste of acids; we add them to soft drinks, salad dressings and spices. Many foods, including citrus fruits and some vegetables, contain acids. Cleaners in our homes contain acids or bases. Acids and bases play important roles in the chemical industry. Currently, approximately 36 million metric tonnes of sulfuric acid are produced annually in the United States alone. Huge quantities of ammonia, urea, and phosphoric acid are also produced annually.
This module will illustrate the chemistry of acid-base reactions and equilibria, and provide you with tools for quantifying the concentrations of acids and bases in solutions.
This is established through an examination of the properties of acids and bases as well as the correct nomenclature for some common inorganic acids and bases. You will explore how our definitions about the behaviour of acids and bases have changed, and why the Brønsted-Lowry definition is the most appropriate one for analysis of proton transfer reactions. You will also carry out volumetric analyses (plural of analysis) involving the technique of titration and explore the ways in which we can quantify the degree of ionisation of acids and the concentrations of solutions, before and after neutralisation.
This module also allows you to analyse how and why the definitions of both an acid and a base have changed over time, and how the current definitions characterise the many chemical reactions of acids. Acids react in particular ways to a variety of substances. These reactions follow a pattern that you will identify and explore in detail.
Acids and bases, and their reactions, are used extensively in everyday life and in the human body. The chemistry of acids and bases contributes to industrial contexts and the environment. Therefore, it is essential that the degree of acidity in these situations is continually monitored. By investigating the qualitative and quantitative properties of acids and bases, you will learn to appreciate the importance of factors such as pH and indicators..
Introduction/Overview:
https://www.youtube.com/watch?v=l7PocftLl-k&list=PLB755F0C836855EAB&index=2 [13.49 mins]
SYLLABUS POINTS
IQ1 What is an acid and what is a base?
1.1 investigate the correct IUPAC nomenclature and properties of common inorganic acids and bases
1.2 predict the products of acid reactions and write balanced equations to represent:
– acids and bases
– acids and carbonates
– acids and metals
1.3 conduct an investigation to demonstrate the preparation and use of indicators as illustrators of the characteristics and properties of acids and bases and their reversible reactions
1.4 investigate applications of neutralisation reactions in everyday life and industrial processes
1.5 conduct a practical investigation to measure the enthalpy of neutralisation
1.6 explore the changes in definitions and models of an acid and a base over time to explain the limitations of each model, including but not limited to:
a) Arrhenius’ theory
b) Brønsted–Lowry theory
IQ2 What is the role of water in solutions of acids and bases?
2.1 conduct a practical investigation to measure the pH of a range of acids and bases
2.2 calculate pH, pOH, hydrogen ion concentration ([H+]) and hydroxide ion concentration ([OH–]) for a range of solutions
2.3 conduct an investigation to demonstrate the use of pH to indicate the differences between the strength of acids and bases
2.4 construct models and/or animations to communicate the differences between strong, weak, concentrated and dilute acids and bases
2.5 calculate the pH of the resultant solution when solutions of acids and/or bases are diluted or mixed
2.6 write ionic equations to represent the dissociation of acids and bases in water, conjugate acid/base pairs in solution and amphiprotic nature of some salts, for example:
– sodium hydrogen carbonate
– potassium dihydrogen phosphate
IQ3 How are solutions of acids and bases analysed?
3.1 conduct practical investigations to analyse the concentration of an unknown acid or base by titration
3.2 investigate titration curves and conductivity graphs to analyse data to indicate characteristic reaction profiles, for example:
– strong acid/strong base
– strong acid/weak base
– weak acid/strong base
3.3 model neutralisation of strong and weak acids and bases using a variety of media
3.4 a) explore the use of Keq for different types of chemical reactions, including but not limited to: dissociation of acids and bases
b) calculate and apply the dissociation constant (Ka) and pKa (pKa = -log10 (Ka)) to determine the difference between strong and weak acids
3.5 explore acid/base analysis techniques that are applied:
a) in industries
b) by Aboriginal and Torres Strait Islander Peoples
c) using digital probes and instruments
3.6 conduct a chemical analysis of a common household substance for its acidity or basicity (ACSCH080), for example:
– soft drink
– wine
– juice
– medicine
3.7 describe the importance of buffers in natural systems
3.8 conduct a practical investigation to prepare a buffer and demonstrate its properties