ICE Tables
Equilibrium Calculations
This section covers various calculations related to chemical equilibrium. Key concepts include $ K_c $ , $ K_p $ , and their relationship, ICE tables, and manipulation of equilibrium expressions.
1. Equilibrium Constant ( $ K $ )
- $ K_c $ : Equilibrium constant expressed in terms of molar concentrations. For the generic reaction: $ aA + bB \rightleftharpoons cC + dD $ , $ K_c = \frac{[C]]^c[D]]^d}{[A]]^a[B]]^b} $
- $ K_p $ : Equilibrium constant expressed in terms of partial pressures. Used for gaseous reactions. $ K_p = \frac{(P_C)^c(P_D)^d}{(P_A)^a(P_B)^b} $
- Relationship between $ K_p $ and $ K_c $ : $ K_p = K_c(RT)^{\Delta n} $ , where $ \Delta n $ is the change in the number of moles of gas (moles of gaseous products - moles of gaseous reactants), R is the ideal gas constant, and T is the temperature in Kelvin.
2. ICE Tables
ICE tables (Initial, Change, Equilibrium) are used to organize information and solve equilibrium problems. They are essential for calculating equilibrium concentrations. ICE Table Examples
3. Calculating Equilibrium Concentrations
This involves using the equilibrium expression ( $ K_c $ or $ K_p $ ) and the ICE table to solve for unknown concentrations. Often requires solving quadratic or cubic equations. Solving Equilibrium Equations
4. Reaction Quotient (Q)
The reaction quotient, $ Q $ , is calculated the same way as $ K $ , but using non-equilibrium concentrations.
- $ Q < K $ : The reaction will proceed to the right (towards products) to reach equilibrium.
- $ Q > K $ : The reaction will proceed to the left (towards reactants) to reach equilibrium.
- $ Q = K $ : The reaction is at equilibrium.
Le Chatelier’s principle predicts the effect of changes in conditions (temperature, pressure, concentration) on an equilibrium system. Le Chateliers Principle
6. Manipulating Equilibrium Expressions
- Reversing a reaction: Inverses the value of K. $ K_{reverse} = \frac{1}{K_{forward}} $
- Multiplying a reaction by a factor: Raises K to the power of that factor. $ K_{new} = K_{original}^n $
- Adding reactions: Multiply the K values of individual reactions to get the K value for the overall reaction.
7. Weak Acid/Base Equilibria
Calculations involving the ionization of weak acids and bases. Involves using the $ K_a $ and $ K_b $ values. Weak Acid/Base Calculations
8. Solubility Equilibria
Calculations involving the solubility of sparingly soluble salts. Involves using the $ K_{sp} $ value. Solubility Equilibria Calculations
Previously Written Notes: (These would be linked to if they were already created)