Chapter 15: Chemical Equilibrium Notes PDF

Chapter 15: Chemical Equilibrium Chapter Outline Section 15.1 Introduction to Equilibrium Section 15.2 Equilibrium Constants Section 15.3 Using Equilibrium Expressions Section 15.4 The Reaction Quotient Section 15.5 Calculations Using ICE Tables Section 15.6 Le Châtelier’s Principle 15.1 Int...

Chapter 15: Chemical Equilibrium Chapter Outline Section 15.1 Introduction to Equilibrium Section 15.2 Equilibrium Constants Section 15.3 Using Equilibrium Expressions Section 15.4 The Reaction Quotient Section 15.5 Calculations Using ICE Tables Section 15.6 Le Châtelier’s Principle 15.1 Introduction to Equilibrium Consider the reaction for the Haber process: 3 H2(g) + N2(g) → 2 NH3 (g) This reaction could also be written in the reverse direction: 2 NH3 (g) → 3 H2 (g) + N2(g) Chemical equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction rateforward = ratereverse A double arrow is used to indicate that a reaction occurs under chemical equilibrium conditions: 3 H2(g) + N2(g) ⇌ 2 NH3(g) 15.1 Introduction to Equilibrium Substances written on the left of the arrow are referred to as reactants and those on the right are products. 3 H2(g) + N2(g) ⇌ 2 NH3(g) The forward reaction refers to substances on the left producing the substances on the right; when this occurs, the reaction proceeds to the right. The reverse reaction refers to substances on the right producing the substances on the left; when this occurs, the reaction proceeds to the left. 15.2 Equilibrium Constants Consider the general reaction: aA + bB ⇌ cC + d D The equilibrium constant, K relates the product and reactant concentrations and can be expressed as: If K = 1, then the rates of the forward and reverse reactions are equally favoured. 𝐶 c 𝐷 d K= a b 𝐴 𝐵 If K >> 1, then the forward reaction is favoured ([products] >> [reactants]) If K