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Chapters 15 and 16 |
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Chapters 15-16 PERFORMANCE OBJECTIVES/Equilibrium At the end of this unit you should be able to: 1. Define dynamic equilibrium in a chemical reaction. 2. Use the reaction quotient, equilibrium constant and concentrations to predict if the reaction is at equilibrium or not, and to predict how the reaction will shift to reach equilibrium. 3. Given a reaction, write the mass action expression for the reaction quotient and equilibrium constant. 4. Given the equilibrium constant for a reaction, determine the equilibrium constant for the reverse reaction, or the reaction multiplied by an integer. Given the equilibrium constants for a series of reactions, determine the equilibrium constant for the sum of those reactions. 5. Calculate a). The Kc or Kp, given the equilibrium concentrations or partial pressures, b). The unknown concentration, given K and all other reactant and product concentrations, c). Equilibrium concentrations given K and initial reactant and product concentrations. 6. Using Le Chatelier's principle, describe the effect of temperature, changing pressure (volume), adding a catalyst, and changing concentrations will have on an equilibrium system 7. Convert between Kc and Kp for a given reaction. 8. Define a heterogeneous equilibrium and write the equilibrium expression for the reaction. Explain why we omit concentration terms for pure liquids and solids and the solvent in a dilute solution in an equilibrium expression. 9. Use the quadratic equation to solve for concentrations in an equilibrium problem. Explain why we can often avoid using the quadratic equation to solve problems. LEARNING OBJECTIVES/Acid & Base Equilibria 0. Define acids and bases using the following definitions, a) Arrhenius, b) Bronstead-Lowry, and c) Lewis. 1. Explain the auto-ionization of H2O and use the ion product of water to calculate [H+], [OH-], pH, and pOH of a given solution, (given any of the four values). 2. Explain the concept of conjugate acid/base, and given a reaction, pick out the conjugate pairs. Given a formula, write the formula of its conjugate acid and conjugate base. 3. Determine if a solution is acidic or basic from the pH, or determine the relative pH if given that a solution is acidic or basic. 4. Explain the difference between a strong acid/base and a weak acid/base. Know the formulas and names of the following strong acids (HCl, HBr, HI, HNO3, H2SO4 (only the first proton is strong), HClO3, HClO4). Given the formula or name, determine if an acid is a strong or weak acid. 5. Given any two of the following for a weak acid or base, determine the third value, a). Ka or Kb, b) initial concentration of weak acid/base, c) [H+], pH, or [OH-]. 6. Explain how we justify neglecting the change in initial concentration of a weak acid or base in equilibrium calculations. When are these simplifications not valid? 7. Use Ka or Kb values to compare relative strengths of acids and bases and their conjugates. 8. Given a substance, write the expected reaction of a substance with water and predict if the solution will be acidic or basic. 9. Calculate the pH and [H+] of a polyprotic acid or the salt of a polyprotic acid, given the acid-disociation constants. 10. Explain why you can usually neglect the second and third ionization constant of a polyprotic acid. 11. Calculate the base ionization constants of a salt of a polyprotic acid, given the acid-disociation constants. 12. Predict if a salt of a polyprotic acid would make an acidic or basic solution based on the acid ionization constants, (for example, given Ka1, Ka2, and Ka3, predict if NaH2PO4 would be make an acidic or basic solution). 13. Given an ionization constant for an acid (base), determine the ionization constant of the conjugate base (acid). 14. Use polarity and relative bond strength, to explain the relative strength of binary and oxyacids. Explain how a metal cation can make a solution acidic. |
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