ASRJC 2024 H2 Chem Chemical Equilibria Notes

2024 JC1 H2 Chemical Equilibria - 1 - 2024/Anderson Serangoon JC/Chemistry ANDERSON SERANGOON JUNIOR COLLEGE H2 CHEMISTRY CHEMICAL EQUILIBRIA Content Instructions 1 Introduction 1.1 Reversible and Irreversible Reactions 1.2 Dynamic Equilibrium 1.3 Closed and Open systems 2 Equilibrium Expressions 2.1 Equilibrium constant, Kc 2.2 Equilibrium constant, Kp 2.3 Equilibrium constant of heterogeneous systems 3 Calculations involving Kc 3.1 Calculating Kc given compositions 3.2 Calculating compositions given Kc 4 Calculations involving Kp 4.1 Calculating Kp given initial partial pressure 4.2 Calculating Kp given mole fractions and total pressure at equilibrium REVIEW Characteristics of Kc and Kp 5 Position of Equilibrium 6 Factors affecting the position of equilibrium 6.1 Changing the concentration 6.2 Changing the pressure 6.3 Changing the temperature 6.4 Presence of Catalyst 7 Application of Principles of Reaction Rates and Equilibria to Industrial Processes – Haber Process 8 Relationship between K and spontaneity of reaction 9 Extra reading on relationship between kinetics and equilibrium

2024 JC1 H2 Chemical Equilibria - 2 - 2024/Anderson Serangoon JC/Chemistry Syllabus objectives CONTENT • Reversible reactions and dynamic equilibrium • Equilibrium constants • Factors affecting chemical equilibria • Le Chatelier’s Principle • The Haber process LEARNING OUTCOMES (a) Explain, in terms of rates of the forward and reverse reactions, what is meant by a reversible reaction and dynamic equilibrium (b) State Le Chatelier’s Principle and apply it to deduce qualitatively (from appropriate information) the effects of changes in concentration, pressure or temperature, on a system at equilibrium (c) Deduce whether changes in concentration, pressure or temperature or the presence of a catalyst affect the value of the equilibrium constant for a reaction (d) Deduce expressions for equilibrium constants in terms of concentrations, Kc, and partial pressures, Kp [treatment of the relationship between Kp and Kc is not required] (e) Calculate the values of equilibrium constants in terms of concentrations or partial pressures from appropriate data (f) Calculate the quantities present at equilibrium, given appropriate data (such calculations will not require the solving of quadratic equations) (g) Show understanding that the position of equilibrium is dependent on the standard Gibbs free energy change of reaction, Go. [Quantitative treatment is not required] (h) Describe and explain the conditions used in the Haber process, as an example of the importance of an understanding of chemical equilibrium in the chemical industry. References 1. Chemistry for Advanced Level; Peter Cann and Peter Hughes 2. Chemistry The Central Science; Brown, Le May, Bursten 8th edition 3. A–Level Chemistry; E.N. Ramsden; 4th Edition

2024 JC1 H2 Chemical Equilibria - 3 - 2024/Ander