CHM1311D 2014 Review Disclaimer The material covered in this review is REPRESENTATIVE of the material for which you will be responsible on the midterm. You are responsible for any material covered in lecture or in homework problems REGARDLESS of whether it is covered in this review.

Chemistry 1311 D You will need to know: You are responsible for any material covered in the lecture notes, DGDs, or midterms, suggested text problems, Sapling, Lecture tools in class questions You are not responsible for material on past year exams that we did not cover (e.g. Gibbs energy, Nernst equation). From the text book (use course notes as a guide) Chapters 1,2,3 and 12 - the Basics isotopes balancing chemical reactions Redox reactions, oxidation states and balancing limiting reagent problems stoichiometric calculation / % yields combustion reactions molecular/structural/empirical formula moles and all the different ways to find them concentration units (molarity, molality, mole fraction, % weight, % volume,

Chemistry 1311 D You will need to know: From the text book Chapters 4 – Gas Laws What is an ideal gas/what is a real gas Pressure units Which R to use when Boyle’s law (constant T) Charles’ law (constant p) Avagodro’s law (constant n) Ideal gas Law Dalton’s Law of partial pressure Significance of mole fraction Quantifying gases by liquid displacement (like in the lab) Gas density

Chemistry 1311 D You will need to know: From the text book Chapter 5 – Thermochemistry Internal energy, U Enthalpy heat and work Exo and Endothermic Calorimetry Hess’s Law Standard Enthalpy of formation for any reaction Van’t Hoff equation

Chemistry 1311 D You will need to know: From the text book Chapters 6 – Quantum and the Atom How do we know it is quantized Orbits, orbitals, quantum numbers Shells, shapes and spin Chapter 7 – Electron Configurations Pauli, Hund and Aufbau Orbital Energy level diagrams Configurations of atoms and ions Anamolies – know some, explain any

Chemistry 1311 D You will need to know: From the text book Chapters 8 – Chemical Bonding Lewis (octets, expanded octets, incomplete octets) Formal charge Resonance What makes a good structure Bond energy and thermochemistry Chapter 9 – Shapes and polarity VSEPR Dipole and polarity

Chemistry 1311 D You will need to know: From the text book Chapters 14 – Kinetics vs. Thermodynamics Rate and concentration Average, Instantaneous, and Initial Reaction Rates Determining the Initial Rate Determining Reaction Orders Determining the Rate Constant Integrated Rate laws (1 st, 2 nd, 0 th ) Reaction Half-Life Activation energy (from rates at different temperatures) Elementary Reactions and Molecularity The Rate-Determining Step The Mechanism and the Rate Law -fast equilibrium, steady state Catalysis, intermediates, poisons

Chemistry 1311 D You will need to know: From the text book Chapters 15 - Equilibrium When use a monodirectional arrow and when to use a bidirectional arrow in writing chemical equations. Be able to write an equilibrium expression for any chemical equation (solids, liquids, gases, solutions)Difference between K and K c Limitations of K c When is K P = K c and when are they different? Know the rules for writing and manipulating equilibrium expressions. Know what it means if K >> 1 or if K << 1 Understand the meaning of the terms “product-favored” and “reactant-favored” Determine whether a reaction is “product-favored” or “reactant-favored” based on the value for K.

Chemistry 1311 D You will need to know: From the text book Chapters 15 – Equilibrium Using quantities to find K Using K to find quantities What if I have both products and reactants? Determine the reaction quotient Q for reactions not in equilibrium. Compare K and Q, will RXN will shift to the right or left or stay where it is. What does it mean for a reaction to shift to the right or to the left? Simplifying assumptions Le Chatelier Determine new equilibrium concentrations/pressures after an additional amount of given species is added Temperature Which R to use in Van’t Hoff equation

Chemistry 1311 D You will need to know: From the text book Chapters 16 – Acids and bases Difference between weak and strong acids and bases (% dissociation) Know when it is appropriate to use a monodirectional arrow and when it is appropriate to use a bidirectional arrow in writing acid base reactions Strong Acids HClO 4 HI HBrH 2 SO 4 HNO 3 Strong Bases Group 1 hydroxides, group 2 hydroxides below Ca Identifying acids and bases (Arrhenius, Brønsted-Lowry and Lewis) Conjugate Acid-Base Pairs Acid-Dissociation Constant (K a ) and relative strength Autoionization and K w

Chemistry 1311 D You will need to know: From the text book Chapters 16 – Acids and bases The pH Scale Calculation of pH and pOH Relationship Between K a and K b Finding K a or K b Given Concentrations Finding Concentrations Given K a or K b Extent of Acid or Base Dissociation Polyprotic Acids Salts That Yield Neutral Solutions Salts That Yield Acidic Solutions Salts That Yield Basic Solutions Salts of Weak Conjugate Acids and Weak Conjugate Bases

Chemistry 1311 D You will need to know: From the text book Chapters 17 – Equilibria in aqueous Equilibria of Acid-Base Buffers and Common-Ion Effect Henderson-Hasselbalch Equation Buffer Capacity and Range Preparing a Buffer Determine buffer pH after addition of base Determine buffer pH after addition of acid Strong Acid–Strong Base Titration Curves -before, after, at equivalence point Weak Acid–Strong Base Titration Curves -before, after, at equivalence point Weak Base–Strong Acid Titration Curves -before, after, at equivalence point

Determining pH Be able to calculate the pH and the concentrations of all species in a solution in the following situations: 1)Dissociation of a strong acid or strong base in water 2)Dissociation of a weak acid or weak base in water 3)Dissociation of a polyprotic acid in water 4)Hydrolysis of a salt that contains: a) cation from a strong acid and anion from a strong base b) cation from a strong acid and anion from a weak base c) cation from a weak acid and anion from a strong base 5)A buffer solution Know how to derive and use the Henderson-Hasselbalch equation. Know the conditions for which the initial concentrations of species can be used in this equation.

Determining pH 6)A buffer solution to which a strong acid or base has been added. 7)During titrations: before, at, and after the equivalence point a)A strong acid and strong base b)A strong acid and weak base c)A weak acid and strong base

Chemistry 1311 D You will need to know: From the text book Chapters 17 – Equilibria in aqueous Define solubility and molar solubility Determine Ksp from ion concentrations. Determine ion concentrations in a solution from the Ksp. Calculate the concentration of an added species that will be necessary to precipitate a given ion. Know how Q is related to Ksp for a saturated, supersaturated, or unsaturated solution. For a solution containing more than one ion, know how much of another ion must be added to cause each ion to precipitate based on Ksp values. Know how the common ion effect affects solubility

A selection of example problems….. A brass sample contains Cu, Sn, Pb and Zn. If g of brass is treated, Sn is converted to g of SnO 2 and Zinc to g Zn 2 P 2 O 7. A second sample of mass g is treated and 300 ml of mM aqueous PbSO 4 solution is prepared. What is the composition (mass %) of each metal in the alloy? A gaseous hydrocarbon occupies ml at 65 o C and 99.2kPa. When burned in excess oxygen, O 2, g of CO 2 and g of H 2 O are obtained. Determine the molecular formula of the hydrocarbon. What is the pH of a 0.3 M trisodium phosphate solution given the acid dissociation constants for phosphoric acid are: K a1 = 7.1x10 -3 ; K a2 = 6.3x10 -8, K a3 = 4.2x10 -13

A selection of example problems….. You would like to determine the equilibrium constant for the oxalate anion, HC 2 O 4 -, a weak acid, by titration. When 15 ml of M KOH are added to a 20 ml solution containing 0.55 g of KHC 2 O 4, the pH is measured and found to be What is the equilibrium constant for the oxalate anion? Solid AgNO 3 is added to a 1.0 L solution of 5.85 g of NaCl and g of K 3 PO 4. The K sp of AgCl and Ag 3 PO 4 are 1.6x and 1.8x10 -18, respectively. Identify the precipitate that forms first. Could you separate the phophate and chloride salts? Draw the Lewis structure, and determine the Valence Shell Electron Pair Repulsion (VSEPR) electron group and molecular geometries of XeF 2 NCO - Include resonance structures and formal charges where appropriate.

A selection of example problems….. The following mechanism, which includes a fast equilibrium step, has been proposed for the reaction of NO with H 2 : What is the overall reaction predicted by this mechanism? What rate law is predicted by this mechanism? How might you prove/disprove the proposed mechanism ? A chemist studies the above reaction as a function of temperature. He finds that increasing the temperature from 25 o C to 38 o C doubles the rate of the reaction. Determine the activation energy for this reaction.

A selection of example problems….. At 25 o C and 1 bar, phosphorus is a solid, P 4 (solid). It can be burned in excess oxygen gas resulting in the formation of P 4 O 10 (s). The reaction of 10.0 g of solid phosphorus generates enough heat to raise the temperature of 2950 g of water from 19.0 o C to 39.0 o C. Calculate the enthalpy of formation P 4 O 10 (s). Heat capacity of liquid water is 4.18 J o C -1 g -1 ; of ice 2.05 J o C -1 g -1 ; of steam J o C -1 g -1 ;  H vap 40.7 kJ mol -1 ;  H fusion = 6.0kJ mol -1 Assign oxidation states to the following: Cl in NaClO4; S in HSO 4 - ; C in CH 3 OH; P in P 4 ;O in O 2 F 2 Balance the following reaction in acid solution: H 2 S + HNO 3  H 2 SO 4 + H 2 O(l) + NO 2 (g)