Study Notes
Reversible reactions are those where products can revert to reactants, indicated by the symbol ⇌. At equilibrium, the rate of the forward reaction equals the rate of the reverse reaction, and concentrations remain constant.
- Reversible Reaction — A reaction where products can revert to reactants. Example: Heating hydrated copper sulfate to form anhydrous copper sulfate and water.
- Equilibrium — A state in a closed system where the forward and reverse reaction rates are equal. Example: The concentrations of reactants and products remain constant.
- Le Chatelier's Principle — If a system at equilibrium is disturbed, it shifts to counteract the change. Example: Increasing pressure in the Haber process shifts equilibrium towards ammonia production.
- Haber Process — Industrial process to synthesize ammonia from nitrogen and hydrogen. Example: N2 (g) + 3H2 (g) ⇌ 2NH3 (g) under high pressure and temperature.
- Contact Process — Industrial process to produce sulfuric acid from sulfur dioxide. Example: 2SO2 (g) + O2 (g) ⇌ 2SO3 (g) using vanadium(V) oxide as a catalyst.
Exam Tips
Key Definitions to Remember
- Reversible Reaction
- Equilibrium
- Le Chatelier's Principle
Common Confusions
- Confusing the direction of equilibrium shift with changes in conditions
- Misunderstanding the role of catalysts in equilibrium
Typical Exam Questions
- What is a reversible reaction? A reaction where products can revert to reactants.
- How does increasing temperature affect an exothermic reaction at equilibrium? It shifts the equilibrium towards the endothermic direction.
- What are the conditions used in the Haber process? High pressure, high temperature, and an iron catalyst.
What Examiners Usually Test
- Understanding of equilibrium and how it is affected by changes in conditions
- Ability to apply Le Chatelier's Principle to predict shifts in equilibrium
- Knowledge of industrial processes like the Haber and Contact processes