CH 220 1st EditionExam # 1 Study Guide Lectures: 1 - 6Lecture 1 This class will focus on H, C, N, O, F, Cl, Br, I (and sometimes P & S)Atomic Structure - Positively charged nucleus that contains protons and neutronsAtomic Number - Often written as (Z), is the number of protons in the atom’s nucleus. Atoms ofa given element always have the same atomic numberAtomic Mass - Often written as (A), is the number of protons plus neutrons. Isotopes are atomsof the same element that have different numbers of neutrons Orbitals describe where electrons are most likely to be with reference to the nucleus, it is a ‘probable’ area and not a definite oneOrbitals further away from the nucleus have the most energyOrbitals are grouped into shells, which can be made up of different types of orbitals, with each orbital being able to be occupied by two electronsCarbon always has four bonds, and adopts a tetrahedron shape so that the bonds have sufficient spacing – the angles between the bonds are approximately 109 degreesAtoms form bonds because the compound that results is more stable than the separate atomsLecture 2 In neutral atoms the number of protons is equal to the number of electronsValence electrons are involved in chemical bonding & reactions, as well as achieving a noble gas configurationOrganic chemistry focuses on nonmetal-nonmetal bonding, known as covalent bonding. Covalently bonded compounds share electrons to achieve their octetIn a covalent bond, the nuclei are attracted to the electron density between atoms, which formsa directional bondLewis structures – bars represent bonded electrons, dots represent lone pairsVSEPR model – Valence Shell Electron Pair Repulsion. The directional nature of bonds dictates the shape of molecules and influences the reactivity of the molecule. Atoms that obey the octetrule can only have 2, 3, or 4 electron regions. The electron regions around atoms repel each other and they get as far away from each other as they can while still being tethered (attracted).One s orbital hybridizes with one p orbital > 2 electron regions > bond angle is 180One s orbital hybridizes with two p orbitals > 3 electron regions (sp2) > bond angle is 120One s orbital hybridizes with all three p orbitals > 4 electron regions (sp3) > bond angle is ~109Lecture 3Functional groups - collection of atoms at a site that have a characteristic behavior in all molecules where it occursi. Alkenes have a carbon carbon double bondii. Alkynes have a carbon carbon triple bondiii. Arenes have an alternating single and double bonds arranged in a ring, sometimes known as an aromatic ring (it doesn’t mean it smells good, it just means that it smells)iv. Alkyl halide has a bond to F, Cl, Br or I (halogens)v. Alcohol has a bond to OHvi. Ether has an oxygen bridge between 2 carbonsvii. Some functional groups have a carbon-oxygen double bonds (these have a family name of Carbonyls) – see diagrams in the inside cover of textbook1. Aldehyde2. Ketone3. Carboxylic acid4. Ester5. Amide6. Acid chlorideAlkanes - compounds with carbon-carbon single bonds and carbon hydrogen bonds, no functional groups (aka hydrocarbons). Formula for alkane with no rings must be CnH2n+2Alkanes with carbons connected to no more than 2 other carbons are straight chain or normal alkanes. Alkanes with one or more carbons connected to 3 or 4 carbons are branched chain alkanesLecture 4IUPAC – Naming straight chain hydrocarbons – identify parent, number carbons, making sure that substituents have the lowest numbers possibleTakes the format: 2-methylpropane, 2-ethyl-7-methyldecae, 2,5-dimethylheptaneExtended, line, condensed structuresIsomers – constitutional isomers (butane, isobutane) – have the same formula but a different structure: different carbon skeletons, different functional groups, different placement of functional groupLecture 5Types of alkyl groups – primary, secondary, tertiary and quaternary alkyl groupsCycloalkanes - saturated hydrocarbons in a ring/circle instead of being in a straight chainCycloalkanes are not isomers of alkanesCyclohexane – most stable conformation is a chair conformation, with 6 axial and 6 equatorial hydrogensNaming cycloalkanes - Find the parent # of carbons in the ring, number substituents, giving the lowest numbers, make sure substituents are listed alphabetically, make sure to write di- or tri- before the substituents if there are multiple of the same typeLecture 6Review session – practice test onlyNeed to know:- Constitutional isomers- Functional groups- Polar covalent bonds- Bond hybridization- Cyclohexane (chair conformation, cis & trans, axial and equatorial)- Alkyl group types (primary, secondary etc)- Lewis structures (either just ALL dots or lines for bonds AND dots for lone pairs- Line bond structure – just lines connecting the atoms, no lone pairs needed- Isomers- Naming branched hydrocarbons- Know how to draw isobutyl, tert-butyl, isopropyl (page 47 in the text book)Make sure to fill in your functional group worksheet, including the names of straight chain hydrocarbons on the