CHEMISTRY 114 

Principles of Chemistry II

Reversible reactions. Equilibrium. Equilibrium constants Kc and Kp. Reaction quotients Qc and Qp. Equilibrium constants and reaction quotients for reaction involving solid components. Effect of temperature, pressure, and concentration on equilibrium. Le Chatelier's principle. Sparingly soluble salts and hydroxides. Solubility. Solubility product. Common-ion effect. Precipitation. Limitations of the solubility product calculations. Arrhenius acids and bases. Mono- and polyfunctional acids and bases. Strong and weak electrolytes. Degree/percent ionization. Ionization constant. Dissociation of water. Water constant. pH and pOH.Buffers. pH of a buffer solution. Titration. Titration curves. Equivalence point and end-of-titration point. Calculations for strong acid/base + strong or weak base/acid systems. Bronsted-Lowry acids and bases. Conjugate acids and bases. Amphiprotic compounds. Salt hydrolysis. Lewis acids and bases.

System and surroundings. Open, closed, and isolated systems. Thermodynamic parameters. Thermodynamic states. Processes. State functions. Work and heat. First law of thermodynamics. Heat of reaction. Energy and enthalpy of reaction. Hess' law. Standard conditions. Standard enthalpy of formation. Spontaneous and nonspontaneous processes. Entropy. Second law of thermodynamics. Free energy and Gibbs free energy. Standard conditions. Standard enthalpy and Gibbs free energy of formation. Concentration dependence of the Gibbs free energy of reaction. Standard Gibbs free energy of reaction and equilibrium constant. Temperature dependence of equilibrium constant. Thermodynamics of redox processes. Nernst equation.

The following topics will have been covered adequately in CHEM 113 in the sections onbonding, molecular structure, intermolecular forces, etc. 

• Hybridization (sp, sp2, sp3)
• Structures of methane, ethane, ethene, ethyne, and benzene
• Cis-trans isomerism in simple disubstituted ethenes, e.g., 1,2-dichloroethene
• Polarity and boiling points of cis-trans isomers
• The importance of hydrogen bonding in relation to boiling points and solubility (illustrate with some organic compounds as well as water, ammonia, etc.)
• Increase in boiling point with molecular size (can be illustrated with homologous series, in addition to the usual examples)
• Resonance, including benzene and the acetate ion

Historical perspective:

Wohler's experiment.

Importance of petroleum deposits as a source of organic compounds:

Fractionation of crude oil.  Examples of ultimate products obtained from petrochemicals. Comment: try to relate organic chemistry to everyday life.

Differences between organic and inorganic compounds:

Common organic families:

Alkanes, alkenes, alkynes, aromatics, alcohols (including the difference between primary, secondary and tertiary), alkyl halides (including the difference between primary, secondary and tertiary), ethers, aldehydes, ketones, carboxylic acids, esters, amines (primary only), amides, amino acids   Comment: an introduction only. A typical objective would be for a student to identify compounds belonging to specified families from a given list.

Common functional groups:

Carbon-carbon double and triple bonds, hydroxyl, carbonyl, carboxyl, amino, ether linkage, benzene ring  Comment: an introduction only. Similarly to the “common organic families” section, a typical objective would be for a student to identify compounds belonging to specified families from a given list.

Common alkyl groups:

Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl. Isomerism.  Introduce/review various types of isomerism, including structural isomers, positional isomers, functional-group isomers, geometric isomers, and "optical" isomers. Comment: can use this to show why systematic nomenclature is important.  Details of optical isomerism and geometrical isomerism to follow later.

IUPAC nomenclature:

Name compounds belonging to the families listed above, except aromatics, ethers, and amines. Comments:  keep it reasonable, e.g. straight- and branched- chain alkanes to about the level of 2,2,4-trimethylpentane; alkenes to the level that one can see the difference between cis and trans, e.g., 2,3-dichloro-2-butene; alkyl halides to the level that tertiary alkyl halides can be named, for example 2-chloro-2-methylpropane.  Limit to one substituent for other families.

Examples: 2-chlorobutanoic acid, 3 -methyl-2-pentanone.  Emphasis should be on naming a wide range of compound types rather than on detailed naming of complex alkanes.

Alkanes:

Conformations of ethane, propane, and butane. Comments:  students are expected to apply these principles to related compounds. Combustion.  Monohalogenation of simple alkanes (methane and ethane), including the mechanism.  Comments: limited to chlorination.  Avoid alkanes where more than one monohalogenated product could be formed.  Can be related back to the discussion of chain reactions in the kinetics section of 113 (if this is still being covered). Introduce fish-hooks. Homolytic and heterolytic bond fission (if not covered previously).

Alkenes:

E/Z nomenclature. Preparation from alcohols and alkyl halides (no mechanisms).  Zaitsev rule (no rearrangements). Addition of H2, Br2 and Cl2. Comments: no mechanisms, illustrate Br2 reaction in the lab.  Discuss industrial significance of H2 reaction. Addition of hydrogen halides. Discussion of Markovnikov's rule in terms of carbocation stability. Comment:  include the mechanism.  Introduce curly (curved) arrows (if not previously covered.)

Alkynes:

Preparation of ethyne from calcium carbide. (Comment: include in lab.) General preparation of alkynes by dehydrohalogenation of vicinal dihalides. Addition of  H2 , Cl2 and Br2.  Comment: illustrate Br2 reaction in lab.

Aromatic compounds:

Review structure of benzene and the concept of aromaticity.  Comment: structure of benzene should have been covered in 113 to a sufficient depth. Examples of aromatic substitution - probably just nitration and halogenation.  Comment: contrast with the addition reactions of alkenes and alkynes.

Alkyl halides:

Review preparation from alkenes. SNl and SN2 mechanisms.  Comments: relate kinetics to Chem 113. Discuss effect of changing alkyl group, but not the nucleophile, leaving group, or solvent. Note that elimination competes and refer back to alkene preparation.

Alcohols:

Differences and similarities of primary, secondary and tertiary illustrated through: (a) reaction with sodium metal; (b) reaction with Lucas' reagent; (c) reaction with oxidizing agents, including potassium dichromate, potassium permanganate, and pyridinium  chlorochromate.  Comment: include all of these reactions in the lab.; note that (c) illustrates redox reactions as used previously in "Vodka" lab. Alcohols in everyday life, including ethylene glycol and glycerol.

Aldehydes and Ketones:

Limit to differences arising due to ease of oxidation of aldehydes.  Comment:  illustrate using Benedict's and/or Fehling's solutions in the lab. Relate to chain form of carbohydrates.

Carboxylic acids:

How structural changes affect pKa.  Comment: relate to previous acid-base chemistry. Reaction with base (e.g. NaOH, NaHC03);  Esterification.  Comment: illustrate latter two in lab.

Esters:

Stereochemistry:

Tetrahedral carbon atoms and recognizing a single chiral centre.   Drawing tetrahedral representations of chiral molecules and assigning R,S configuration.  Understanding optical activity and the concept of dextro and laevo enantiomers.

Amines:

Behaviour as bases.  Comment: relate to acid-base chemistry. Reaction with carboxylic acid derivatives to form amides.  Comment: leads into later discussion of peptides.

Amino acids:

Structures.  Comments: need to be able to recognize whether the side-chain is acidic, basic, or neutral (ties in with Biology). Zwitterions.  Comments: identify the predominant species at a given pH.  Perhaps incorporate an amino acid into the pH titration lab. Chirality.  Comments:  avoid assignment of R/S. Peptide formation (without going into detail) Nylon.  Comment: prepare nylon in the lab

Aspartame:

Students need to be able to develop synthetic strategies using the reactions mentioned above.  For example: “suggest a synthesis of (a) 2-butanone from 1-butene, (b) 2-butyne from ethene.

Comment: This is a very important skill required for subsequent organic courses.