NSWChemistry

Module 5: Equilibrium and Acid Reactions

8 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

Inquiry Question 5: How are acids and bases defined and how do they behave in aqueous solution?

Conduct an investigation to perform titrations of strong acid and strong base, weak acid and strong base, and weak base and strong acid, and analyse the data to determine concentration, pH at the equivalence point, and appropriate indicator selection
A focused answer to the HSC Chemistry Module 5 dot point on titrations. The four titration curve shapes, equivalence vs end point, indicator selection rules, calculating unknown concentrations from titration data, and worked HSC past exam questions.
7 min answer →
Investigate the Brønsted-Lowry theory of acids and bases, including conjugate acid/base pairs and the behaviour of amphiprotic species
A focused answer to the HSC Chemistry Module 5 dot point on Brønsted-Lowry acid-base theory. Definitions, conjugate acid-base pairs, amphiprotic species (water and bicarbonate), how the theory extends Arrhenius, and the worked HSC past exam questions.
6 min answer →
Investigate the structure and properties of buffer systems, including their composition, how they resist pH change, and their importance in natural systems such as blood
A focused answer to the HSC Chemistry Module 5 dot point on buffer systems. The composition of a buffer (weak acid plus conjugate base), how the equilibrium resists pH change, the Henderson-Hasselbalch equation, the carbonic acid blood buffer, and worked HSC past exam questions.
7 min answer →
Conduct investigations and perform calculations to determine the pH and pOH of strong and weak acids and bases, applying the formulae pH equals negative log of hydrogen ion concentration, and pH plus pOH equals 14
A focused answer to the HSC Chemistry Module 5 dot point on pH and pOH. The pH and pOH formulae, the auto-ionisation of water, strong vs weak acid/base calculations using ICE tables, dilution effects, and worked HSC past exam questions.
7 min answer →

Inquiry Question 3: How can the position of equilibrium be described and what does the equilibrium constant represent?

Deduce the equilibrium expression (in terms of Keq) for homogeneous reactions, and perform calculations to find the value of Keq and concentrations of substances within an equilibrium system
A focused answer to the HSC Chemistry Module 5 dot point on the equilibrium constant. Deriving the Keq expression, interpreting its magnitude, the ICE table method, and worked HSC calculations for finding Keq and equilibrium concentrations.
7 min answer →

Inquiry Question 2: What factors affect equilibrium and how?

Investigate the effects of temperature, concentration, volume and/or pressure on a system at equilibrium and explain how Le Chatelier's principle can be used to predict such effects
A focused answer to the HSC Chemistry Module 5 dot point on Le Chatelier's principle. How concentration, pressure, volume and temperature shift equilibrium position, the role of catalysts, the Haber process worked example, and the past HSC questions markers reward.
7 min answer →

Inquiry Question 4: How does solubility relate to chemical equilibrium and the position of equilibrium?

Predict the solubility of an ionic substance by applying solubility equilibrium principles, and perform calculations involving the solubility product constant (Ksp) and the ionic product
A focused answer to the HSC Chemistry Module 5 dot point on the solubility product. Writing Ksp expressions, predicting precipitation using the ionic product Q vs Ksp, the common ion effect, and worked HSC calculations for solubility and precipitation.
7 min answer →

Inquiry Question 1: What happens when chemical reactions do not go through to completion?

Investigate the differences between static and dynamic equilibrium, and reversible and non-reversible reactions, using practical examples
A focused answer to the HSC Chemistry Module 5 dot point on static and dynamic equilibrium. The definitions, the macroscopic vs molecular view, classic practical examples (NO2/N2O4, cobalt complexes, sealed water), and the worked HSC past exam questions.
6 min answer →