Dr. Streit Exam 3 Study Guide
Dr. Streit Exam 3 Study Guide CHEM 1030 - 003
Popular in Fundamentals Chemistry I
Popular in Chemistry
This 6 page Study Guide was uploaded by Rachel Ferrell on Monday April 18, 2016. The Study Guide belongs to CHEM 1030 - 003 at Auburn University taught by John D Gorden in Fall 2015. Since its upload, it has received 122 views. For similar materials see Fundamentals Chemistry I in Chemistry at Auburn University.
Reviews for Dr. Streit Exam 3 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/18/16
Rachel Ferrell CHEM 1030 Exam 3 Study Guide: Ch 7-‐10 Chapter 7: Vocab: • Valence Shell Electron Pair Repulsion Model (VSEPR) Model o Basic idea of model→electrons repel each other, therefore they will arrange themselves to be as far apart as possible from each other • Electron Domains= can be lone pairs, single, double or triple bonds Shape Number of Number of Lone Bond Angle Hybridization Electron Pairs Domains Octahedron 6 0 90 Sp d3 2 Square Pyramidal 6 1 90 Sp d3 2 3 2 Square Planar 6 2 90 Sp d 3 Trigonal 5 0 120,90 Sp d Bipyramidal See-‐Saw 5 1 120,90 Sp d 3 T-‐Shape 5 2 120, 90 Sp d Linear 5 3 120,90 Sp d Tetrahedral 4 0 109.5 Sp Trigonal 4 1 109.5 Sp Pyramidal 3 Bent 4 2 109.5 Sp Trigonal Planar 3 0 120 Sp 2 2 Bent 3 1 120 Sp Linear 2 0 180 sp • Electron Domain Geometries= will either be linear, trigonal planar, tetrahedral, trigonal bipyramidal, or octahedron (lone pairs are not taken into account) • Molecular Geometry= takes into account lone pairs • Bond Angles= lone pairs and double/triple bonds make bond angle slightly smaller • Dispersion= all molecules have this intermolecular force • Diople-‐Dipole= attractions between polar molecules (NOF) • Hydrogen Bonding= type of dipole; has a H bonded to N,O, or F • Ion-‐Dipole Interaction= attraction between polar ions o Bigger positive charge=stronger interaction (attracted to the partially negative side of the polar molecule) • Valence Bond Theory= =atoms share electrons when atomic orbitals overlap • Hybridization= = mixing of atomic orbitals can account for observed bond angles in molecules that could not be described by a direct overlap of atomic orbitals o Basically valence bond theory doesn’t work for all molecules so they make new orbitals by combining them o Depending on electron domain→what hybridization is • Sigma Bond-‐= forms when sp hybrid orbitals on C atom overlap o free rotation around bond axis • Pi Bond= forms when unhybridized p orbitals overlap o no free rotation o Single Bond: 1 sigma o Double bond: 1 sigma, 1 pi o Triple bond: 1 sigma, 2 pi • Example Problems: o 1.) CH 4 § look at lewis structure § 4 electon domains→ 4 hybrid orbitals needed § ground state: 2s 2p 1 3 § excited state: 2s 2p § therefore→ 4 sp orbitals needed o 2.) PCl 5 § look at lewis structure § 5 electron domains→ 5 hybrid orbitals needed § ground state: 3s 3p 1 3 1 § excited state: 3s 3p 3d § therefore→ 5 sp d hybrid orbitals Chapter 8: Vocab: • Combination reaction= 2 or more reactants combine to form a product o ex. NH 3+ HCl→NH Cl 4 • Decomposition= 2 or more products form a reactant o ex. CaCO →CaO3 + CO 2 • Combustion= substance burns in presence of O ; c2ntains C and H and produces CO 2 and H2O o Ex. x HyO z + 2 O → C2 +2 H O • Limiting Reactant= reactant used up first in a reaction • Excess reactant= left over after reactant is gone • Theoretical Yield= amount of product that forms when all limiting reactant reacts to form desired products • Actual Yield= Amount that forms from actual reaction ▯▯▯▯▯▯ ▯▯▯▯▯ • Percent Yield= x 100 ▯▯▯▯▯▯▯▯▯▯▯ ▯▯▯▯▯ Things to know/ Calculations: • Combustion Analysis: • Limiting Reactant problems o To find Limiting reactant: § 1.)Convert masses to moles. § 2.) Divide by the coefficient to the molecule in the equation § 3.) Whichever number is smaller→limiting reactant o After finding limiting reactant: § 1.) Take moles of limiting reactant and multiply by stoichiometric ratio between limiting reactant and the molecule you are converting to § 2.) Convert from moles to grams Chapter 9: Vocab: • electrolyte= dissolves in water to yield a solution that conducts electricity • nonelectrolyte= dissolves in water bu does not conduct electricity (doesn’t dissociate into ions) • dissociation= process by which ionic compound breaks into ions when it dissolves • ionization=process by which molecular compound forms ions when it dissolves • Strong Electrolytes= dissociates completely when dissolved in water (none of original is left in products o Strong acids→produces H+ (all acids are electrolytes) § HCl § HBr § HI § HClO 3 § HClO 4 § HNO 3 § H 2O 4 *Need to memorize these o Strong Base→produces OH-‐ § LiOH § NaOH § KOH § RbOH § CsOH § Ca(OH) 2 § Ba(OH) 2 • Weak Electrolytes= does not dissociate completely; some of original is left as a product • Precipitation Reaction= an insoluble solid is formed that separates from the solution o Involves ionic compounds o 2 reactants are (aq) and 1 of products is a (s) • Solubility Rules o • Molecular equation= compounds are written in the equation like normal • Ionic Equation= compounds are separated into ions so it is easier to see which ions are part of the reaction o Spectator ions= when ionic equation is written, these are on both sides; therefore are not part of the reaction o ex. Molecular equation: Na SO (aq2 4 Ba(OH) (aq) → 2 2NaOH(aq) + BaSO (s) 4 o Ionic equation4 2Na + SO + Ba + 2OH → 2Na 4+ 2OH + BaSO + -‐ o Na and OH are spectator ions • Redox Reaction= electrons are transferred from one reactant to the other o LEO goes GER o Oxidation= loses electrons (becomes more positive) o Reduction= gains electrons (becomes more negative) o Oxidizing agent= whatever is being reduced o Reducing Agent= whatever is being oxidized o Tip: figure out what is being oxidized/reduced first, and then the opposites are the agents • Oxidation Number= charge an atom would have if electrons transferred completely o How to find oxidation numbers: § Always start with known oxidation numbers: • Oxygen→always -‐2 • Hydrogen→almost always +1 • Halogens(Group 7A)→ almost always -‐1 • Group 1A→almost always +1 • Group 2A→ almost always +2 § Then fill in remaining charges to that it creates a neutral molecule § Don’t forget to multiply charges by subscripts to get overall charge Concepts to Know: • How to write Precipitation Rxn: o 1.) Write/balance equation; predict products § cations trade anions o 2.)Write ionic equation by separating into ions o 3.) Cancel Spectator ions o 4.) If they all cancel→not a precipitation reaction • Assigning Oxidation Numbers: o 1.) SF →4=+4, F=-‐4 o 2.) Fe O3→ 4 Fe=2.6, -‐2 o 3.) KMnO → 4= +1, Mn=+7, O=-‐2 • Types of Redox Reactions: o Displacement= ions replace each other § ex. Zn + C2Cl →ZnCl 2 + Cu o Combination=elements form a compound § ex. 2 + 2 3H → 2N3 o Decomposition= elements of compound break into elements § ex. 2NaH→ 2Na + H2 o Combustion= starts with Carbon compound plus oxygen and releases CO and water2 § Ex. CH4 + 22O → 2 CO 2 2H O • Concentration/Molarity Problems: ???????????????????? ???????????????????????? o ???????????????????????????????? ???? = ???? ???????????????????????????????? ▯▯▯ o ???? = ▯ o ???????????? = ????×???? o for these problems just plug in; make sure volume is in L and if they give you grams just convert to moles. • Dilution Problems: o Moles of solute before dilution= moles of solute after dilution o M 1X L1 = 2 M 2 X L Chapter 10: Vocab: • System= part of the universe that is of specific interest (where reaction is happening) • Surroundings= everything else • Thermochemistry= study of heat (transfer of thermal energy) in a reaction o Heat unit: Joules • Exothermic= reaction releases heat/energy to surroundings o When q or ∆H is negative • Endothermic= reaction absorbs heat/energy from surroundings o When q or ∆H is positive • Enthalpy= ∆H or q (heat absorbed or released in a reaction) • Specific Heat= the amount of heat required to raise the temperature of 1 g of substance by 1 degree C • Hess’s Law= change in enthalpy occurs that occurs when reactants are converted to products in a reaction is the same no matter how many steps taken to get there Equations to Know and Understand: • ∆U system =−∆???? surroundings o ∆U= change in energy • ∆U= q + w o q= heat o w= work o w is (+) when work being done on system o w is (-‐) when work done by system • w= -‐P∆V o w= work o P= external opposing pressure o ∆V= change in volume • ∆H = H(products)-‐ H(reactants) • q= ms∆T o q= heat o m= mass (g) o s= specific heat (J/gxC) o ∆T= change in temp (C) o ***Make equation (-‐) if solving for heat of surroundings (normal equation solves for heat of system) Types of Problems: • Thermochemical Equations (Hess’s Law) o Steps: o 1.) You can multiply both sides by a number, but then must multiply ∆H by that factor o 2.) To reverse products and reactants→change sign of ∆H o 3.) Keep manipulating until equations are the same; then add up ∆Hs • **look at problems at the end of the chapter, that is the best way to understand these problems
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'