Unit 2 Review

Unit 2 - A solution is a homogeneous mixture of 2 or more substanes, The substance in greatest quantity is the solvent. The other substances are solutes - An electrolyte (conducts electroaly) frums a solution that contains cons, NaCl(s) + H₂O Nat + Ci a non-electrolyte dessolos but does not form cons i.e. sugar. a weak electrolyte only partially dissociates. i.e. Acetic Acid HC2H2O2+ + 1H302 + H2O → H₂O + H30 96% 2% - Precipitation reaction. 2 solutions are mited and form a solid (precipitate) These are Pb(NO3)2 + 2KI PbI2 + 2KNO3 also called exchange (metatheses) reactions - Net Sonic Equations: - Write mobculn equation. - Reurite showry cons that are framed - Solubility rules. - Soleds and are never conized - pure liquids Water is never conized. - Identify and cancel spectator cions (cons that are the some in the reactants and products) page 1 i.e. A solution of silver nitrate is added to a solution of potassium chloride AgNO3 + KCl → AgCl + KNO3 - molecular Ag++NO3-+K++Cl- → AgCl + K++NO3- ionic Ag++Cl- → AgCl net ionic Hints: (1) any time the prompt says solution it's ionic (2) In this case, K+, NO3- are spectators (3) Don't forget charges on ions. Acids: Donate H+ Bases: Accept H+ Neutralization Reaction: Strong Acid + Strong Base → Water + Salt HCl + NaOH → NaCl + H2O molecular. H++Cl-+Na++OH- → Na++Cl-+H2O ionic H++OH- → H2O net ionic. Weak Acid + Strong Base → Water + Salt HC2H3O2 + NaOH → H2O + NaC2H3O2 molecular. HC2H3O2 + Na++OH- → H2O + Na++C2H3O2- ionic HC2H3O2 + OH- → H2O + C2H3O2- net ionic Hints: (1) Weak acids are always written as molecular (2) C2H3O2- and HC2H3O2 the acetates are different, they are not spectators poge 2 Bas formation reactions! 2HCI t rotten eff oder Na₂S H₂Scg) + 2NaCl molecular 2H++ 5² H₂sg 2 net conic Bubbles { HCl + Na₂CO₃ H₂CO₃ + NaCl. mabalar 2H+ + -2 →H2O + CO2 t net mic { pungent odor. 2HCl + Na₂50, H₂503 + 2 Nal'ı molecular 2H++ So H₂O + SO2 net wnic Oxidatim-Reduction Reaction! Oxidation is losing e Beductim is gaming Ca(s) + 2H → e Cata + H₂ Ca loses 2e oxidized 214+ game ze reduced. 2e. - elements are always "O" oxidation state Balencing Redox Equations: Copper metal added to Nifique Acid step1: ㅗ Cu(s) +- 그어줘요 +2 +40+20 +42 Become coefficients + Le le NO₂+ H₂O 42 Cu(s) Cu page 3 Step 2: Balance O by addey H₂O I Culs) + H+ 2NO I Ca²+2 NO₂+ 3H20 1. Coefficient of H2052. Step 3: Balance It by addey Ht + +2 1 Culs) + 4H + 210031ch+2002+240 i. coefficient of Ht is 4 Quick check: compare Total charge of rectoons & products They must must be equal (+2+2) Molarity = mol solute / situs of solution - 49.0g phosphoric acid is deserved. in enough water in To manke 1500ml of solution, What is the molarity? 49gx Imoe HyPay = 05mol/1.5L = 33 moler. P04 988 - In 05 M AlCl3 what is the molarity of CT? • 5 mol AlCl3 3 mol CI X IL Ind AIC/3 1.5m = 1.5M Page 4 MV MV Problems. 3 types: dilution, gravimetric analysis, titration Dilution: What volume of 2M IHCI can produced from 100ml of 12 M HCI? (12m)(.12) 2m(voi) .6L = vol. Sravemetue Analysis: What volume of 5m NaCl is required to precipitate all of the Pb from 200ml of 3M Pb(NO3)2 Step1: Write balanced equation Pb(NO)2 + 2NaCl PbCl2 + 2NaNO3 | Step 2: (.3m) (.2LX2moler) = (5m)(imoler) (vol) I Pb 24L = Vol NaCl of Don't forget to caccount for stoichiometre relation Titration: What volume of. 2m Ba(OH), is required to neutralize 400 ml of .5 M HCl. Rememba in teration the mal Ht equal the mol OH at the neutralizaten (equivalence) point, page 5 Thermochemisty Chergy, Capocity to produce hat or unck, ile Energy: energy of moten KE= 12 mass(velocity) Potenteal Energ: every that can be counted to work Heet; energy transfer between 2 abjects Wrk: facex distance System: Loght bis tand y chees sention Exothermic: hat flows out of the syatom ce. combistion Endothermic: heat flous into system is. cold pack work: Force = mass x acceleraten → Kg x m/32 = foule Pressure: Pre • 2 aure = Force mea= K9ms m 2 = Kys in l Pressure x volume = kgs'm-'x m'=15 m'= poule i: at constant Pressure wak perfined on The siptem. is ! W= -PAV taw of conscisten a her musted fum one form to another - entry a not le created or destinga - the energy of the uncerse is constent SE=g+ W 4 heat flow; wis work. 4 sEb L0, the system loses energy, exothernic I DE is so, the suptem youns snergy, endothermec Flange: Colla the french te sumon digo th do 39 solo of I foun Entlalpy; sit is beat flow at content presure. AH = LAH txn Products 20H. reactants AH LO, exothermic AH>0, endathermic Example: NaOHs) + HiO → Na+OH sH= =43 K//mol what is AH fo dessolony. 17g NaOH - 43 kJ mol tIme! - x 14g = -15 kJ= sHexn page 7