Chem Final Sheet

September 4, 2017 | Author: eskinan | Category: Chemical Polarity, Chemical Bond, Ion, Ionic Bonding, Solution
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Matter and Numbers (lead 0≠sigfig!) extensive (amt matters): mass, volume intensive: density, color, texture, boiling pure substances: element-1 element, can’t be broken down (C, O2), molecule-2+ atoms chemically combined (H2, H2Osmallest bit), compound-2+ different atoms chemically combined (C2O, H2O) mixtures: physically combined; hetero: separated(oil/water).suspension: particles are big enough that they separate out (sand/water) homo: mixed/dissolved; solution-particles do not reflect light. colloid-light is spread/dispersed (fog) The Atom mass # = protons + neutrons atomic # = protons = chemical symbol charge = # protons - # electrons e- configuration: staircase→=gainers (gain until isoelectronic [same # e] w/ noble gas) ←staircase=losers; element loses 4 or fewer e- to become isoe-ic; OR 1) remove e- from highest principle energy level (highest coefficient; p b4 s) 2) full, half-filled, or empty d-orbital Nomenclature ionic compound: start w/ metal (pos 1st) covalent compound (2 nonmetals): name 1st element w/ prefixes (except mono), take root of 2nd element followed by –ide using prefixes [mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca]; [#]hydrate acids: -ate-ic, ite-ous. hydro—ic: HF, HCl, HBr, HI, H2S, H2Se, H2Te, HCN HO F B R I N Cl; P4 S8 (when by itself) Reaction Types (*=bold choice) *synthesis: metal+nonmetalionic cmpd combustion: __+O2CO2 +H2O decomposition: reactantprod+prod -chlorate: Sn(ClO3)4SnCl4 + 6 O2 -carbonate: K2CO3K2O + O2 -bicar: Zn(HCO3) 2 ZnO+2CO2+H2O -ammonium: NH4ClNH3+HCl (acid) *single replacement: element+ionic cmpd new element+new ionic cmpd (or NR) double replacement: 2 ionic cmpds  2 new ionic cmpds; reactants always aq; if all 4 aq, NR. ionic-take apart into ions -net-ionic: Al+3(aq)+3OH-1(aq)Al(OH)3(s) excess reactant: start factor label w/ limiting & x by mol ratio, gets *used up*

The Mole (atomic weight=MM) 6.022x1023 atoms in one mole % composition by mass: × # atoms by mass and ÷ by total mass (all added) empirical formula: change %g, g mol, ÷ everything by smallest # mol molecular: given mass ÷ MM; × EmpF weighted avg MM: (MMA)(AbundanceA [.%])+(MMB)(AbundanceB)= ? g/mol Stoichiometry balance eq, convert given info to mol, × by mol ratio, convert to required units. % yield=got/shouldagot Periodicity horizontal=periods, vertical=groups d-block=transition, f-block=inner-trans. 1A=alkali (except H), 2A=alkaline earth, 7A=halogen, 8A=noble gases, borders 2 sides of staircase=metalloids (except Al) left→right: nucleus gets stronger. top → bot: more completed energy levels of eatomic radius: distance from nucleus outermost e-; decreases→/increases ↓ electronegativity: ability of atom to pull eto its nucleus; increases →/ decreases ↓ ionic radius: radius of most common ion formed; 2x decrease →/increase ↓ ionization energy: energy required to remove 1 e- from a neutral gas atom; general increase →/decrease ↓ second+ ie: energy required to remove 1 e- from +1 ion; count e- needed to NB, then add 1 to get the highest IE metallic properties: ease with which an element loses e-; decrease→/increase ↓ Lewis Dot Structures –valence e-’s are e-’s in outermost/highest energy level ionic compounds do not share: Na Cl covalent: add up all valence e-, determine central atom (1st listed, unless H is 1st), distribute e- so all get 8, except H gets 2 single bond-1 pair e-; double=2 pairs resonance: one extra e- pair resonates ex) O — S — O ↔ O — S — O under the octet: only B; ex) BeCl2, BCl3 over the octet: central atom in 3rd period & greater can exceed octet-d orbital available; ex) PCl5, SF6 free radicals: odd # e-, very reactive; higer e-neg gets 8 e-, lower gets 7 (NO) bond angles: tetrahedron-109.5˚; e- bond atoms & repel other e-. lone pair-107˚;

pair only has 1 job-to repel other e-; other e- get pushed down. 2 pairs-104.5˚ bond angles based on VSEPR: valence shell electron pair repulsion; e- pairs around central atom orient themselves as far away from each other as possible! polarity: polar molecules are CHARGED (have a positive and negative end); based on e-neg: ability to pull e- in chem. bond nonpolar: elements in cmpd all the same -compound contains only C and H -things touching central atom=identical polar: if it is an ion (no deltas needed!) delta=partial ex) charge; needed for polar mcs ONLY Condensed States (liquid or solid) london dispersion: nonpolar mc + polar mc; also noble gases if forced. form temporary dipoles (distribution of charge uneven; e- bounce back and forth) ex) Cl Cl Cl Cl dipole-dipole: polar mc + polar mc; the dipoles are permanent; ex) H Br hydrogen bonding: subset of dipoledipole; when H ex) with O, N, or F (based on huge difference of e-neg) ionic bonding: metal ion + nonmetal ion one atom loses, other=isoe-ic w/ NB metallic bonding: metal ion + metal ion electrons move freely-delocalized; nuclei compete for e- attraction. plug-creates ripple effect through the wire (e- repel), makes a current and conducts electricity! network solids: single, giant molecule; series of covalent bonds-cont. network ion-dipole: ionic cmpd + polar cmpd neg side of ion is attracted to pos side of polar mc with a dipole; strong attraction like dissolves like: np + np, p + p strong attraction, will dissolve/mix dipole-induced dipole: polar + nonpolar each pos end on mc bonds to neg end; slight attraction will form, deltas are small ion-induced dipole: ionic + nonpolar ion causes dipole, disturbs arrangement of e- in nonpolar mc; weak attraction SOAP.nonpolar end bonds w/ oil,

while polar end bonds w/water surface tension: every atom in H2O involved in H-bonding, making a net at surface of water-can support light things ice properties: less dense, higher volumeH-bonding creates gaps b/w mcs in ice melting/boiling: stronger forces, higher melting/boiling pt & melts/boils slower phase diagrams: SL: melt LG: boil GS: deposit SG: sublime GL: condense LS: freeze Gas Laws ˚C=273.15 + K L=mL/1000 atm=mm Hg/760 mm Hg=760 atm 14.7 PSI = 29.92 in Hg = 760 mm Hg = 760 torr = 1atm = 101.325 KPa kinetic molecular theory: O=true 1) mc of gas are dimensionless pts 2 mc of gas are in constant, random, ○ straight-line motion 3 higher temp, mc gas moves faster *○ 4 collisions b/w mc gas are elastic (no ○ energy lost) 5) mc of gas do not have attractive or repulsive forces Boye’s Law: pressure ↑, volume ↓ Charles’ Law: temp ↑, volume ↑ Gay-Lussac’s Law: temp ↑, pressure ↑ combined gas law: nothing held constant, use gas laws/stoich! units: L, K, and atm ideal gas law: PV=nRT R=.08206 atm, L, # mol (g/MM), K Dalton’s Law: Ptotal= Ptoxic gas+Pwater vapor Graham’s Law:

Solutions ^high MM, low rate^ M of solution: mol solute÷L solution how much solute in sol: mol=M×L how to prepare given sol: __ g + enough water to make __ L of solution coligative properties: properties of solutions, depend on # particles of solute -boiling pt elevation: more solute, higher boiling pt. (more bonds to break) -freezing pt depression: solute mixes w/ solvent particles, need to get them out of

solution; lower temp., slow solute mcs down, solute mcs attract to each other ΔT=K×m×# particles of solute K=freezing/boiling pt constant m=molality=mol solute/kg solvent osmosis: movement of water across semipermeable membrane from higher concentrationlower concentration Thermodynamics (1 kcal=4.18 kJ) calorimetry: heat is exchanged heating curve:

q=heat, c=specific heat=heat required to raise 1 g of a substance 1˚C (cal/g˚C) ΔHfusion: heat required to melt 1 g of a substance; ΔH vaporization: heat required to boil 1 g of a substance (cal/g) same phase: q=m×c×ΔT (final-initial) melting; q=m×ΔHfusion boiling: q=m× ΔH vaporization exothermic-substance gives off heat tea problem:

chicken soup problem:

enthalpy: ΔH of reaction; balance equation, multiply coefficients by H values, add up reactant/product side, ΔH=products−reactants entropy: products are more disordered, entropy of reaction is increasing 2 factors: states of matter-GL, decrease # mc-7mc5 mc, decrease (neg. entropy) -balance equation, multiply coefficients by S values, ΔS=products-reactants spontaneity:spontaneous reaction: continue on its own once started exothermic endothermic

ΔG=ΔH−TΔ temp in K, change J to kJ if positive, reaction is not spontaneous if negative, reaction is spontaneous set ΔG to zero to find the change point (temp. at which reaction goes from spontaneous to nonspontaneous and v.v.) bond energy: different way to calculate ΔH: balance equation, multiply energy value by coefficients; add together, ΔH=reactants−products (in kcal) Equilibrium collision theory: for a reaction to occur, mcs must collide with sufficient energy and at appropriate angles factors-rate of rxn: 1) temp ↑, rate ↑ 2) concentration: [ ] ↑, rate ↑ 3) surface area: SA ↑, rate ↑ 4) nature of rctnt: lower act. enrg., rate ↑ 5) catalysts: lower act enrg, are not eaten! 2 types: homogeneous (same phase; ex: Cl in ozone depletion), heterogeneous (different phases; ex: catalytic converter) rate equations: rate=K[A]coeff[B] coeff aA+bB=cC+dD

[ ]=M

liquids and solids are not included in eq.! Ksp=solubility product constant/solid dissolved in water ex)

Le Chatelier’s: if stress placed on rxn at equilibrium, it will adjust to compensate -shifts away from added, shifts towards removed (solids or liquids will NOT affect the equilibrium; only aq and g) -increase in pressure, rxn shifts to the side w/ fewer gas mc -decrease in pressure, rxn shifts to the side w/ more gas mc Acids and Bases Arrhenius: acid-something that produces H + ions when mixed with water (HCl) base-something that produces OH – ions when mixed with water (KOH, H3PO4) Lewis: acid-e- acceptor (gainers, pos. ions) base-e- donor (losers, metals) Bronsted-Loury: acid-proton donor (H+) base-proton acceptor (neg. ions, NH3, H2O) *amphoteric=can be acid or base

strong acids: HCl, HBr, HI, HNO3, HClO4, H2SO4 (will all go to products side; disassociates completely) strong bases: LiOH, NaOH, KOH, RbOH, CsOH weak bases: NH3, —NH, —NH2 1×10 -14 = [H3O+1][OH-1] pH = -log [H3O+1] 14 = pH + pOH [H3O+1]= 10-pH neutralization: 2 solutions— MA × LA × #H= MB × LB × #OH Mconcentrated × Vconcentrated = Mdilute × Vdilute

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