Module 5: Equilibrium and Acid Reactions
10 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?
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.
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.
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.
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.
Inquiry Question 2: What factors affect equilibrium and how?
A focused answer to the HSC Chemistry Module 5 dot point on collision theory. How concentration, temperature, surface area and catalysts change reaction rate by changing collision frequency and the fraction of successful collisions, the Maxwell-Boltzmann link to activation energy, and why a faster approach to equilibrium does not change its final position.
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.
Inquiry Question 1: What happens when chemical reactions do not go through to completion?
A focused answer to the HSC Chemistry Module 5 dot point on entropy, enthalpy and Gibbs free energy. What entropy and enthalpy each measure, why delta-G = delta-H minus T delta-S decides spontaneity, why an exothermic reaction can still be non-spontaneous, and why most reactions stop at equilibrium rather than completion.
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.
Inquiry Question 3: How can the position of equilibrium be described and what does the equilibrium constant represent?
Inquiry Question 4: How does solubility relate to chemical equilibrium and the position of equilibrium?