# of regionsbond anglehybridizationExam # 1 Study Guide Lectures: 1 - 7Lecture 1 (August 22)Atomic Structure:- Understand what an atom looks like and where the nucleus, protons, and electrons are.- Know subshells (s, p, d, f) and how to write the electron configuration of an elementso Rules for how electrons are placed in orbitals: Aufbau Principle: fill lowest energy orbitals first (1s -> 2s -> 2p -> 3s ->) Pauli Exclusion Principle: there can only be 2 electrons per orbital and the spins must face the opposite ways (one up and one down) Hund’s Rule: add 1 electron to each orbital equal in energy first, then go back and add a 2nd electron to these orbitals if there is enough- Know how to draw Lewis Dot Structure: element surrounded by dots to equal the number of electrons in the valence shellUnderstand the octet rule: each element wants 8 electrons so it could have a noble gas configurations. Chemical bonds form in an attempt to com-plete the octet through sharing electrons between atoms. Be able to draw atoms bonding by sharing electrons. CHEM 333 1st Edi-tion Complete the octet by: Losing or gaining electrons Sharing electrons with one or more other atoms (covalent bond)Lecture 2 (August 27) - Know the difference between polar and nonpolar bondso Nonpolar: bond where electrons are shared equallyo Polar: when elements do not share electrons equally (need two different ele-ments for this to happen) - Know how to predict polarityo Predict by electronegativty. When drawing arrows on elements to show polarity, draw arrow going towards the most electronegative element between the two ele-ments that are bonded.- Understand how to find formal chargeo # of valence electrons (group #) - # of electrons in lone pairs - (1/2) shared elec-trons- Know how to identify how regions of density and what bond angles resulto Regions of electron density include a lone pair, single bond, double bond, or triple bond. 4 regions of electrons density: angles are 109.5° 3 regions of electron density: angles are 120° 2 regions of electron density: angles are 180°- Understand resonance structures and how to draw them o Rules for resonance structures: All structures must have the same number of electrons (electrons cannot just “dissappear,” they must go somewhere) All structures must be valid Lewis structures Never more atoms, only electrons. Double bonds and lone pairs can shift, but do not break single bonds. Number of paired and unpaired electrons must remain the same. Negative charge should go on the more electronegative atomo Rules for deciding resonance structure that is major contributor: Filled valence shell (octet) structure contributes more Maximum number of covalent bonds contributes more Structure with the least separation of unlike charges contributes moreLecture 3 (August 29)- Understand what s and p orbitals look like- Know how electrons act as waves- Understand hybridizationo Tetrahedral shape: 1s + 3p -> sp3109.5°25% s charactero Trigonal planar shape: 1s + 2p -> sp2120°33% s charactero Linear shape: 1s + 1p -> sp180°50% s characterLecture 4 (September 3) - Know how to identify hybridization of each atom. This chart can be used for reference.# of regions bond angle hybridization1 --- s2180°sp3120° sp24109.5° sp3-- Know how to identify a polar moleculeo Must have polar bonds and epends on arrangement of polar bondsA. Molecular dipole: vector sum of bond dipolesa. Examples: The more polar something is, the greater molecular dipole (�) is. � = 0 when molecule is nonpolar.- Know what a molecular dipole iso Vector sum of bond dipoles. The more polar something is, the greater the molec-ular dipole is. Molecular dipole = 0 when molecule is nonpolar.Lecture 5 (September 5)- Be able to identify the following types of hydrocarbons:o alkaneo alkeneo alkyne- Be able to identify the following functional groups:o alkyl halideso alcoholso etherso amineso aldehydeso ketoneso carboxylic acidso esterso amideso nitriles- Understand the difference between ion-ion forces, dipole-dipole forces, and hydrogen bondingo Ion-Ion Forces: Strong electrostatic forces between positive and negative charges. Takes high energy to break interaction, has a high melting point, and has a high boiling point.o Dipole-Dipole: Some molecules are polar and have a permanent dipole. They ori-ent so the positive part of one molecule lines with the negative part of another. This causes strong interactions with each other.o Hydrogen Bonds: Strong interaction between heteroatom with H and heteroatom with a lone pair. Found with O, N, and F. These bonds are weaker than covalent bonds, but stronger than dipole-dipole.oLecture 6 (September 10) - Understand dispersion forceso Very weak intermolecular forces of attraction resulting from the interaction be-tween temporary induced dipoleso Happen at any time where there can be polarization of electron desnisty because electrons moveo Gives a temporary dipole moment that can induce a temporary dipole in a mole-cule next to ito The attractive force is temporary- Know the trends in physical propertieso Small vs. larger molecules Small molecules: less surface area = less interaction = weaker attraction Larger molecules: more surface area = more interaction = stronger attrac-tiono Boiling points: stronger intermolecular interactions increase the boiling pointo Solubilities: “Like dissolves like.” For example, oil dissolves in oil and water dis-solves in water.Polar and ionic solids usually dissolve in polar solventsPolar liquids are miscible, meaning they can mix togetherNonpolar solids are soluble in nonpolar solventsNonpolar solvents are miscible, meaning they can mix together- Know the difference in hydrophobic and hydrophilic molecules- Know the difference in homolytic and heterolytic cleavage- Understand how to tell if there something is an acid or a baseo Bronsted acid: substance that gives up a proton (proton donor) Acid-H H2O Acid⇌- H3O+o Bronsted base: substance that can accept a proton (proton acceptor) Base H2O Base-H OH⇌- Know how to tell if it is a strong or weak acido Measure acidity and get a pKa value- Know trends in pKao Larger pKa = weaker acido Small pKa = stronger acido Weak acid = stronger conjugate baseo Strong acid = weaker conjugate base- Memorize these pKa valueso C2H6, pKa = 50o , pKa = 44o NH2 - H, pKa = 38o , pKa = 25o , pKa =