ACSI HL Organic Chemistry notes 2021.docx (1)

IBDP Chemistry HL/ Organic Chemistry Page 1 Anglo−Chinese School (Independent) Year 6 (2021) IBDP HL Chemistry (IBDP syllabus Topic 10) 10.1 Fundamentals of Organic Chemistry − Essential Idea: Organic chemistry focuses on the chemistry of compounds containing carbon. 10.2 Functional Group Chemistry − Essential Idea: Structure, bonding and chemical reactions involving functional group interconversions are key strands in organic chemistry. TOPIC 10 ORGANIC CHEMISTRY

IBDP Chemistry HL/ Organic Chemistry Page 2 (IBDP syllabus Topic 20) 20.1 Types of Organic Reactions − Essential Idea: Key organic reaction types include nucleophilic substitution, electrophilic addition, electrophilic substitution and redox reactions. Reaction mechanisms vary and help in understanding the different types of reaction taking place. 20.2 Synthetic Routes − Essential Idea: Organic synthesis is the systematic preparation of a compound from a widely available starting material or the synthesis of a compound via a synthetic route that often can involve a series of different steps. 20.3 Stereoisomerism − Essential Idea: Stereoisomerism involves isomers which have different arrangements of atoms in space but do not differ in connectivity or bond multiplicity (ie whether single, double or triple) between the isomers themselves.

IBDP Chemistry HL/ Organic Chemistry Page 3 10.1 Fundamentals of organic chemistry Nature of science: Serendipity and scientific discoveries—PTFE and superglue. (1.4) Ethical implications—drugs, additives and pesticides can have harmful effects on both people and the environment. (4.5) Understandings: • A homologous series is a series of compounds of the same family, with the same general formula, which differ from each other by a common structural unit. • Structural formulas can be represented in full and condensed format. • Structural isomers are compounds with the same molecular formula but different arrangements of atoms. • Functional groups are the reactive parts of molecules. • Saturated compounds contain single bonds only and unsaturated compounds contain double or triple bonds. • Benzene is an aromatic, unsaturated hydrocarbon. Applications and skills: • Explanation of the trends in boiling points of members of a homologous series. • Distinction between empirical, molecular and structural formulas. • Identification of different classes: alkanes, alkenes, alkynes, halogenoalkanes, alcohols, ethers, aldehydes, ketones, esters, carboxylic acids, amines, amides, nitriles and arenes. • Identification of typical functional groups in molecules eg phenyl, hydroxyl, carbonyl, carboxyl, carboxamide, aldehyde, ester, ether, amine, nitrile, alkyl, alkenyl and alkynyl. • Construction of 3-D models (real or virtual) of organic molecules. • Application of IUPAC rules in the nomenclature of straight-chain and branched chain isomers. • Identification of primary, secondary and tertiary carbon atoms in halogenoalkanes and alcohols and primary, secondary and tertiary nitrogen atoms in amines. • Discussion of the structure of benzene using physical and chemical evidence. Guidance: • Skeletal formulas should be discussed in the course. • The general formulas (eg CnH 2n+2) of alkanes, alkenes, alkynes, ketones, alcohols, aldehydes and carboxylic acids should be known. • The distinction between class names and functional group names needs to be made. Eg for OH, hydroxyl is the functional group whereas alcohol is the class name. • The following nomenclature should be covered: o non-cyclic alkanes and halogenoalkanes up to halohexanes. o alkenes up to hexene and alkynes up to hexyne. o compounds up to six carbon atoms (in the basic chain for nomenclature purposes) containing only one of the classes of functional groups: alcohols, ethers, aldehydes, halogenoalkanes, ketones, esters and carboxylic acids.

IBDP Chemistry HL/ Organic Chemistry Page 4 10.2 Functional group chemistry Nature of science: Use of data—much of the progress that has been made to date in the developments and applications of scientific research can be mapped back to key organic chemical reactions involving functional group interconversions. (3.1) Understandings: Alkanes: • Alkanes have low reactivity and undergo free-radical substitution reactions. Alkenes: • Alkenes are more reactive than alkanes and undergo addition reactions. • Bromine water can be used to distinguish between alkenes and alkanes. Alcohols: • Alcohols undergo nucleophilic substitution reactions with acids (also called esterification or condensation) and some undergo oxidation reactions. Halogenoalkanes: • Halogenoalkanes are more reactive than alkanes. They can undergo (nucleophilic) substitution reactions. A nucleophile is an electron -rich species containing a lone pair that it donates to an electron-deficient carbon. Polymers: • Addition polymers consist of a wide range of monomers and form the basis of the plastics industry. Benzene: • Benzene does not readily undergo addition reactions but does undergo electrophilic substitution reactions. Applications and skills: Alkanes: • Writing equations for the complete and incomplete combustion of hydrocarbons. • Explanation of the reaction of methane and ethane with halogens in terms of a free -radical substitution mechanism involving photochemical homolytic fission. Alkenes: • Writing equations for the reactions of alkenes with hydrogen and halogens and of symmetrical alkenes with hydrogen halides and water. • Outline of the addition polymerization of alkenes. • Relationship between the structure of the monomer to the polymer and repeating unit. Alcohols: • Writing equations for the complete combustion of alcohols. • Writing equations for the oxidation reactions of primary and secondary alcohols (using acidified potassium dichromate(VI) or potassium manganate(VII) as oxidizing agents). Explanation of distillation and reflux in the isolation of the aldehyde and carboxylic acid products. • Writing the equation for the condensation reaction of an alcohol with a carboxylic acid, in the presence of a catalyst (eg concentrated sulfuric acid) to form an ester. Halogenoalkanes: • Writing the equation for the substitution reactions of halogenoalkanes with aqueous sodium hydroxide.

IBDP Chemistry HL/ Organic Chemistry Page 5 Guidance: • Reference should be made to initiation, propagation and termination steps in free -radical substitution reactions. Free radicals should be represented by a single dot. • The mechanisms of SN1 and SN2 and electrophilic substitution reactions are not required. 20.1 Types of organic reactions Nature of science: Looking for trends and discrepancies—by understanding different types of organic reactions and their mechanisms, it is possible to synthesize new compounds with novel properties which can then be used in several applications. Organic reaction types fall into a number of different categories. (3.1) Collaboration and ethical implications —scientists have collaborated to work on investigating the synthesis of new pathways and have considered the ethical and environmental implications of adopting green chemistry. (4.1, 4.5) Understandings: Nucleophilic Substitution Reactions: • SN1 represents a nucleophilic unimolecular substitution reaction and S N2 represents a nucleophilic bimolecular substitution reaction. S N1 involves a carbocation intermediate. S N2 involves a concerted reaction with a transition state. • For tertiary halogenoalkanes the predominant mechanism is S N1 and for primary halogenoalkanes it is SN2. Both mechanisms occur for secondary halogenoalkanes. • The rate determining step (sl