CHAPTER OBJECTIVES
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CHEM 1190 Chapter Objectives Chapter 13 – Properties of Solutions Recognize examples of solutions Know definition of solubility Know definition of saturated solution Know definition of supersaturated solution Know definition of miscible / immiscible Understand the dynamic nature of saturated solution dissolution crystallization Understand the physical factors of solution formation Intermolecular forces – ‘like dissolves like’ Enthalpy – enthalpy of solvation usually negative - as charge density of ion increases, enthalpy of hydration increases Entropy – disorder / in all systems, total entropy increases Understand the factors affecting solubility External Pressure Temperature – Careful: Factors are different for gas in liquids and solids in liquids Know Henry’s Law and be able to do Henry’s Law problems: c k P Know the five concentration units discussed Mass Percent Parts per million (billion) Mole Fraction Molarity Molality Be able to convert between concentration units Know that colligative properties depend only on the number of solute particles Be able to find the concentration of solute particles for ionic and molecular solutes Understand physically Raoult’s Law: PA x A PA0 Be able to do problems using Raoult’s Law Understand the relationship between vapor pressure and boiling point Understand the relationship between Raoult’s Law and boiling point elevation Be able to do boiling point elevation problems: Tb = Kb m Be able to do freezing point depression problems: Tf = Kf m Know what is a semipermeable membrane Know what is osmosis Know why semipermeable membranes are essential for osmosis Know what is osmotic pressure Know what is reverse osmosis and why it is important Be able to solve problems with the osmotic pressure equation: V = nRT Be solve problems using osmotic pressure to calculate the molar mass of a solute Know the difference between an ideal and a nonideal solution Interpret microscopically what positive and negative deviations from ideality for solutions 2 Know what a colloid is Know difference between dissolution and dispersion Know what the Tyndall effect is and its importance Know the general structure of a soap or detergent molecule Know how soaps and detergents work Know what a micelle is and how they form Know what an emulsion is Chapter 14 – Chemical Kinetics Understand the definition of reaction rate: molesof B t Understand the factors which affect reaction rate Concentration of reactants Temperature of reaction Catalysis Surface Area Be able to an average reaction rate from concentration versus time data Understand what is meant by an instantaneous reaction rate Understand how the stoichiometry of a reaction affects the rate of formation and rate of disappearance of chemical species Know the general form of a reaction rate law: = k [A]m [B]n [C]p … Be calculate rate orders and the rate constant of a reaction rate law given concentration versus rate data Know what is meant by a first-order reaction Be able to use the concentration versus time relationship for a first-order reaction to solve problems: ln [A] - ln [A0] = - kt Know the difference between common and natural logarithms Know the algebraic rules for logarithms ln (ab) = ln (a) + ln (b) ln (a/b) = ln (a) – ln (b) ln(ab) = b ln (a) eln a = a ln ea = a Know how to use ln [A] - ln [A0] = - kt to plot concentration versus time data on a linear plot Know how to read a linear first-order concentration versus time plot to find initial concentration and the first-order rate constant Know what is the half-life of a first-order reaction Know how to use ln [A] - ln [A0] = - kt to calculate the half-life of a first-order reaction Know what is meant by a second-order reaction Be able to use the concentration versus time relationship for a second-order reaction to solve 1 1 kt problems A A 0 1 1 k t to plot concentration versus time data on a linear plot Know how to use A A 0 Know how to read a linear second-order concentration versus time plot to find initial concentration and the second-order rate constant 3 1 1 k t to calculate the half-life of a second-order reaction A A 0 Compare the expressions for a first-order reaction with the expressions for a second-order reaction, especially half-lives Know what is meant by a zeroth-order reaction and know the consequences of zeroth-order reaction. Know the collision theory of reactions Understand how the collision theory of reactions helps to explain the factors that affect reaction rate Know what is meant by activation energy Know what is meant by activated complex Be able to read and interpret a reaction energy diagram Know how to use Ea Using the Arrhenius equation, k A e RT , understand the relationships between the rate constant and the temperature or activation energy Be able to calculate a rate constant given a temperature, activation energy and frequency factor Be able to use a ratio of Arrhenius equations to calculate the activation energy given rate constants at two different temperatures Be able to rearrange Arrhenius equation to plot rate constant versus temperature on a linear plot Know what is meant by catalysis Understand the role of activation energy in catalysis Know the difference between heterogeneous and homogeneous catalysis Know what is meant by adsorption Know what is meant by an elementary reaction Know how to put together elementary reaction in a reaction mechanism to find an overall reaction Know the reaction rate laws for elementary reactions Know what is meant by an intermediate Know how to identify an intermediate in a reaction mechanism Know how to identify a catalyst in a reaction mechanism Know how to write a reaction rate law given a simple reaction mechanism Chapter 15 – Introduction to Equilibria Understand relationship between equilibrium and reaction rates Know examples of physical and chemical equililbria Be able to write an equilibrium expression for a given equilibrium Be able to calculate the value of the equilibrium constant given equilibrium concentrations or pressures Understand how the equilibrium constant value gives information about preferred chemical species Know what is meant by homogeneous equilibria and heterogeneous equilibria Know how to write an equilibrium expression for a heterogeneous equilibrium Be able to solve for unknown equilibrium concentrations or pressures given an equilibrium and initial concentrations or pressures - Know when to approximate changes as small, i. e., when is ‘x’ small - Know when to use quadratic equation and how to use it. n Know relationship between Kc and Kp: K p K c RT 4 Know what is LeChâtelier’s principle Know the factors that can be changed to disturb equilibria Know how LeChâtelier’s principle predicts the response to the disturbance of equilibria Know how value of reaction quotient predicts direction of reaction Know how temperature affects exothermic and endothermic equilibria Know how pressure affects gas phase equilibria Know the effect of catalysis on equilibria Chapter 16 – Acids and Bases Know what is meant by an Arrhenius acid/base Know what is meant by a Brønsted/Lowry acid or base Know what is meant conjugate acid or conjugate base Be able to identify conjugate acid/base pairs in an acid/base reaction Know what is meant by a Lewis acid or base Be able to compare and contrast the Arrhenius, Brønsted/Lowry and Lewis acid/base theories Be able to identify an acid/base as strong or weak Know what is meant by a neutralization reaction Know what is meant by the autoionization of a solvent (especially water) Know that Kw = 1.0 10-14 at 25 C Know how calculate [H+] given [OH-] or calculate [OH-] given [H+] Know the hydronium ion concept Know the definition of pH and other “p” scales Know the relationship between pH and pOH and pKw Understand the relationship between the strength of an acid (base) the strength of its conjugate base (acid) Be able to calculate the pH of a solution of a mixture of strong acids Be able to calculate the pH or pOH of a solution of a mixture of strong bases Know how the chemical structure of a weak acid affects its strength Be able to write an equilibrium expression for the dissociation of a weak acid Be able to calculate the pH of a weak acid solution Be able to calculate the Ka of a weak acid given its pH and concentration Know the two common sources for weak bases: conjugate bases and nitrogen compounds Be able to write an equilibrium expression for the dissociation of a weak base Know the relationship between Ka and Kb Be able to calculate the pH or pOH of a weak base solution Be able to calculate the percent ionization of a weak acid or base Know how percent ionization relates to acid/base dissociation constant Know what is meant by a polyprotic acid Understand the dissociation process in a polyprotic acid Based on Ka values, be able to identify the stronger conjugate base Based on Kb values, be able to identify the stronger conjugate acid Know what is meant by hydrolysis Know how anions and cations affect hydrolysis Be able to estimate whether an ionic solution is acidic, basic or neutral 5 Chapter 17 – Buffers/Titrations/Solubility Equilibria Know what is meant by the common-ion effect Be able to relate the common-ion effect to LeChâtelier’s principle Be able to calculate the pH of solution of mixtures of conjugate acid/base pairs Know what is meant by a buffer Know how the common-ion effect relates to buffers Know why buffers are important Know what is meant by buffer capacity [ base] Know the Henderson-Hasselbalch equation: pH pK a log [acid ] Know the applicability of the Henderson-Hasselbalch equation Understand the equivalence of the Henderson-Hasselbalch equation and acid-dissociation expression Be able to use the Henderson-Hasselbalch equation to calculate the pH of solutions of mixtures of conjugate acid/base pairs Be able to design a buffer system using the Henderson-Hasselbalch equation and a table of aciddissociation constants Know what is meant by a titration Know what is meant by an indicator Know the difference between endpoint and equivalence point Be able to select an indicator for an acid/base titration Know the difference between a deadstop titration and a potentiometric titration Be able to read a titration curve - Be able to properly label axes - Identify if sample is strong or weak acid or base - Identify if sample is polyprotic - Identify equivalence points - Identify pKa or pKb of weak acid and bases - Identify buffer regions Know how to identify what part of the titration curve a system is at based on the titration data - Weak acid (or base) [Initial conditions] - Buffer - Weak base (or acid) [Equivalence point] - Strong base (or acid) [Excess titrant] Be able to calculate the pH of a titration at any point in the titration curve given titration data Be able to write a solubility product expression for a given solubility equilibrium Know the relationship between molar solubility and Ksp Know the relationship between mass solubility and molar solubility Be able to calculate solubility given Ksp Be able to calculate Ksp given solubility Understand how the common-ion effect affects solubility Understand how the separation of ions occurs through selective precipitation Be able to calculate concentrations of ions needed for selective precipitation Be able to use a table of Ksp to design a separation of ions based on selective precipitation Understand how pH may affect solubility 6 Know what is meant by a coordination complex Know how Lewis acid/base theory explains coordination complexes Know the definition for the formation constant of complex ion Understand how complexation may affect solubility Know what is an amphoteric ion Know how to judge which ions are amphoteric Chapter 19 – Thermodynamics Know what is meant by a spontaneous process Be able to identify a process as spontaneous or nonspontaneous Know what is meant by a reversible process Be able to identify a process as reversible or irreversible Know the first law of thermodynamics: E = q + w Understand the significance of the first law of thermodynamics Know the sign convention for heat and work Know what is meant by entropy Be able to compare qualitatively systems with different amounts of entropy q rev Know the thermodynamic definition of entropy: S T Be able to use the thermodynamic definition of entropy to calculate entropy given heat and temperature (especially for phase transitions) Know the second law of thermodynamics: S univ 0 Understand the difference of system and surroundings Be able to explain how the entropy of a system can decrease and not violate the 2nd law of thermodynamics Know the three types of molecular motion: translational, rotational, vibrational Know what is meant by degree of freedom For a given molecule, know the number of degrees of freedom for each mode of molecular motion Know the third law of thermodynamics: The entropy of a perfect crystal is zero at absolute zero Understand the consequences of the third law Be able to calculate standard entropy changes of chemical reactions Know what is meant by Gibbs free energy Know the definition of Gibbs free energy Know the Gibbs-Helmholtz equation: G = H – T S Understand how the definition of Gibbs free energy relates to the second law of thermodynamics Know how to decide the spontaneity of a process using Gibbs free energy Know that the value of the Gibbs free energy yields the maximum work available for a reaction Understand the significance of the magnitude of Gibbs free energy Be able to calculate standard Gibbs free energy changes for chemical reactions Understand the temperature dependence of the Gibbs free energy Be able to calculate the Gibbs free energy at a nonstandard temperature of a chemical reaction using thermodynamic tables of standard enthalpy and standard entropy and the GibbsHelmholtz equation Know the difference between Gibbs free energy, G, and standard Gibbs free energy, G 7 Know how to write and calculate the reaction quotient for gas phase and aqueous reactions Know what is a reaction quotient Know relationship between reaction quotient and Gibbs free energy: G G 0 RT ln Q Be able to calculate Gibbs free energy of a chemical reaction given concentrations or pressure and standard Gibbs free energy and use the result to predict direction of reaction Know the relationship between equilibrium constant and standard Gibbs free energy: G = -RT ln K Know the difference between reaction quotient and equilibrium expression Be able to calculate the equilibrium constant given a standard Gibbs free energy of reaction Be able to calculate the standard Gibbs free energy of reaction given an equilibrium constant Chapter 20 – Electrochemistry Be able to assign an oxidation number to an atom within a molecule Know the definition of oxidation Know the definition of reduction Know what is meant by an oxidizing agent Know what is meant by a reducing agent Be able to identify the oxidizing and reducing agents in a redox reaction Know what is meant by a half-reaction Understand the complementary nature of oxidation and reduction and the conservation of charge Be able to balance redox equations in acidic and basis solutions Know what is meant by a voltaic cell Know what is meant by an anode Know what is meant by a cathode Know what is meant by a salt bridge Understand why salt bridges are necessary in voltaic cells Be able to sketch and label the parts within a voltaic cell Know what is meant by electromotive force (voltage) Know the definition for the SI unit of EMF Know what is meant by electrical current Understand the relationship between electrical current and voltage Know what is meant by a standard reduction potential Be able to calculate the cell potential of a redox reaction at standard conditions using standard reduction potentials Know the reference potential for standard reduction potential and understand why it is necessary Know how to judge the strength of oxidizing and reducing agents based on standard reduction potentials Understand the relationship between free energy and cell potential: G = -n F E Know how to calculate the Gibbs free energy of a reaction given a balanced redox equation and a cell potential Know how to calculate the cell potential of a reaction given a balanced redox equation and the Gibbs free energy 8 Understand the relationship between the reaction quotient and the cell potential via the Nernst equation: E E 0 RT ln Q nF Be able to calculate the cell potential for a nonstandard cell given a standard cell potential and the reaction quotient Understand how a concentration gradient can drive an electrochemical reaction Know what is meant by electrolysis Be able to sketch and identify the parts of an electrolytic cell Be able to compare and contrast voltaic cells and electrolytic cells Understand the possible complications in the electrolytic of an aqueous solution Know the relationship between current and charge Be able to do problems involving electrolysis Understand corrosion as an electrochemical process Know what is meant by a sacrificial electrode and why they are important Chapter 21 – Nuclear Chemistry Know what is meant by radioactivity Know the different forms of radioactivity: alpha decay, beta decay, gamma decay, fission Know what is meant by an alpha particle Know the three forms of beta decay: electron emission, positron emission, electron capture Know what is meant by a neutrino Know what is meant by a positron Know the difference between spontaneous fission and induced fission Know what is meant by a chain reaction Know the three forces in a nucleus Be able to name the nuclear force that mediates each mode of radioactivity Be draw a rough sketch of a table of nuclides Know what is meant by a band of stability Know the ‘even, odd’ rules of nuclear stability Know what is meant by a magic number Be able to predict nuclear stability based on ‘even, odd’ rules Be able to predict route of radioactivity for an unstable nuclide Be able to write a balanced nuclear reaction for a radioactive decay Know what is meant by cross section Be able to compare and contrast nuclear reaction and chemical reactions Know that nuclear decay processes follow first-order kinetics Be able to do problems associated with first-order kinetics Know what is meant by activity Know what is a Geiger counter and what it measures Understand the significance of Einstein’s equation E = mc2 Be able to use Einstein’s equation to calculate energy changes in nuclear processes
