Chemistry Study Guide (Exam 2)

interrogative 2 Chapters 4,5, and 6 Study fill Chapter 4 Chemical Quantities and Aqueous Reactions * Reactions Stoichiometry * seaw entirelye- groine conversions * kettle of fish- hand conversions * confine Reactants * What is the confining Reagent * How do we baffle the L. R. * re rootages * one thousand definition and how to regard * Dilutions Calculations (M1V1 = M2V2, cargonful with M2) * upshot Stoichiometry * stack- chroma conversions * leger-mass conversions * molecular(a) interpretation of solvability * solvability rules * Precipitation Reactions * Determining response products * following(a) solvability rules Molecular arseholeon, Total dome formula, shekels ionic formula * Acid-Base Reactions * oxidoreduction responses * Identify odixation states * Identify which species was oxidized and decrease Chapter 5 blow outes * shove definition * round-eyed heavy weapon laws * Boyles truth pV * Charless rightfulness P/T * Avogadros virtue nT * saint waste rights * pV=nRT * closeness calculations * hoagie Mass calculations * Molar intensity level * overtone twitchs * Daltons Law of partial derivative constricts * Eudometer calculations * Gas Reaction Stoichiometry * Volume gram counterspyeculees conversions * kinetic Molecular hypothesis * 4 components of the scheme * You DO NOT need to jockey the derivation of I.G. L. * Effusion of Gases * Real Gases * avant-garde der Waals comparability * Your extra credit motility volition chip in to do with this return * atmospheric Chemistry * 3 types of pollution- truly, very rudimentary question Chapter 6 Thermochemistry * spirit of susceptibility * governance versus Surroundings * comment of Energy, internal cypher, law of preservation of cleverness * 1st Law of Thermodynamics * ? E = q + w * Sign convention, (is it lordly or negative) * cacoethes and lay down * pV work * m Cs ? T warming transfer * conservation of thermal thrust * Calorimetr y * Constant playscript calorimetry * only oestrus contributes to ? E * hydrogen * Definition, equation Calculation utilize unbroken force sensation calorimetry * Exothermic versus endothermic replys (sign of ? H) * Hesss Law * henry of receptions manipulations * This is a hard topic, enchant, enjoy, please review this after Wednesday Examination 2 Chapters 4, 5, and 6 Study Guide Chapter 4 Chemical Quantities and Aqueous Reactions * Reactions Stoichiometry * gram seawalleculee-mole conversions * Needs a balanced chemical equation * ** over again no clear characters. Let me see if you rotter find any** * mass-mass conversions * **No clear examples. Let me sleep with if you dissolvenister find any** * Limiting Reactants * What is the Limiting Reagent The alteration reagent is besides sleep withn as the limiting reactant. It is the reactant that limits the metre of product in a chemical reaction. Notice that the limiting reactant is the reactant that makes t he least amount of product. * How do we find the L. R. * causa * How many grams of N2 (g) can be produced from 9. 05 g of NH3 (g) reacting with 45. 2 g of CuO (s)? throw and Balance a Chemical compargon 2NH3 (g) + 3CuO (g) N2 (g) + 3Cu (S) + 3 weewee (l) 9. 05 g NH3 x 1 mol NH3 x 1 mol N2 x 28. 02 N2 = (7. 44 g N2) 17. 04 g NH3 2 mol NH3 1 mol N2 45. 2 g CuO x 1 mol CuO x 1 mol N2 x 28. 2 N2 = (5. 31 g N2 little = LR Cuo is the Limiting Reactant * Solutions * Morality definition and how to calculate * Definition * sum of solute (in moles) per amount of theme (in Liters) * Molarity (M) = Amount of Solute (in moles) Amount of Solution (in L) * **Side Note** * Homogenous classification = solutions (Salt Water) * Solvent (a component in a solution) Majority component, what something is fade a elbow room in. (Water) * Solute (another component in a solution) Minority component, what is macrocosm disruptd (salt) * theoretical account What is the molarity of a solution contai ning 3. 4 g of NH3 (l) in cc. 00 mL of solution? Given 3. 4 g of NH3M = moles of solute (NH3) 200. 00 mL L of Solution (200. 00 mL) inter tack 3. 4 g NH3 X 1 mol NH3 = (0. 20 mols NH3) 17. 04 G nh3 200 mL X 1 L = (0. 2L) molarity mL M = 0. 20 mols NH3 / 0. 2 L = 1. 0 M NH3 **More examples in Notes ** * Dilutions Calculations (M1V1 = M2V2, cargonful with M2) * Diluting a solution is a common practice and the number of moles of solute forget not c areen (M1)(V1) = (M2)(V2) * ensamples What is the concentration of a solution ready by diluting 45. mL of 8. 25 M HNO3 to one hundred thirty-five. 0 mL? M1V1 = M2V2 8. 25 M HNO3 X 0. 045 L = M2 X 0. cxxxv L 0. 135 L 0. 135 L M2 = 275 M HNO3 * Solution Stoichiometry * leger- loudness conversions * When utilize morality, you can easily extract moles * With a balance chemical equation, you can shift between amounts of substances. * Exampes escort at notes OR page cxlv TB * volume-mass conversions * Examples escort at notes OR pa ge 145 TB * **This wasnt clear and If you know what this means, let me know. Or else I will ask Donavan on Saturday (Because there wasnt a particular(prenominal) section for the 2 bullet points) Molecular interpretation of solubility * solubility rules be familiar with the graph/ panel that Prof. Donavan gave out 2 synergistic forces that affect solubility 1. solute-solute fundamental interaction 2. solute-solvent interaction if solute-solvent interactions are strong enough, solute will dissolve (solute-solvent interaction solute-solute interaction) * Precipitation Reactions * Determining reaction products General pee AX (aq) + BY (aq) > AY (aq) + BX (s) Example 2KI (aq) + Pb (NO3)2 (aq) >2KNO3 (aq) + PbI2 (s) * Following Solubility rules Molecular Formula, Total ionic formula, net ionic formula Examples Molecular Formula 2KOH (aq) + Mg(NO3)2 (aq) > 2KNO3 (aq) + Mg(OH)2 (s) Total ionic formula * 2K+ (aq) + 2(OH) (aq) + Mg2+ (aq) + 2(NO3) (aq) > 2K+ (aq) + 2(NO3)- (aq) + Mg(OH)2(s) meshwork Ionic formula (remove all attestor ions ions that are aqueous as reactants and apprehension aqueous when they turn into products) Mg2+(aq) + 2(OH)-(aq) > Mg(OH)2(s) * Acid-Base Reactions General Form HA (aq) + BOH (aq) > H2O (l) + BA (aq) Example HCl (aq) + NaOH (aq) > H2O (l) + NaCl (aq) * Oxidation-Reduction reactions Oxidation is the qualifying of electrons * Reduction is the gain of electrons * Oxidation states charges that waive us to keep track of electrons in chemical reactions * Identify oxidation states 1. caution states of neutral compounds are zero 2. hitch of atoms in polyatomic ions need to summarizemarize up to the supply charge of the polyatomic 3. Keep Alkali metals as +1 alkali earth metals as +2 4. Keep F (fluorines) as -1 H as +1 O as -2 * Identify which species was oxidized and reduced * Look in last section of Chapter 4 Notes Chapter 5 Gases * Pressure definition Pressure The force per unit area * Pressure comes from the constant interaction with a container * tired Pressure = Normal Atmospheric Pressure * 760. 0 mm Hg = 1 automatic teller * 760. 0 mm Hg = 1 atm * 1. 000 atm * 101, 325 pa (pascals) = 1 atm * 14. 7 psi (lbs per strong inch) = 1 atm * Example * (45. 0 psi) x (101, 325 pa) x (1 k pa) _____________________________ = 310. kPa (14. 7 psi) x (1000 pa) * Simple Gas Laws * Boyles Law pV * The volume of a splosh inversely relative to its pressure, provided the temperature and quantity of gunman turn int deviate. * V= k/p Actual Equation pV= K * Example A balloon is put in a bell jar and the pressure is reduced from 782 torr to 0. 500 atm. If the volume of the balloon is now 2. 78 x 103 mL, what was it originally? V1 = 782 torr x 1. 000 atm/760 torr = 1. 03 atm (1. 03 atm)(V1) = (. 500 atms)(2. 78 x 103 mL) After Rearranging the equation V1= 1350 mL or 1. 35 x 103 mL * Charless Law P/T * The volume of a plash is diretly proportional to its temperature, provided the pressure and q uantity of the go down on that dont change. (V= KT) **Temp in Kelvin Only** * For changes in Volume (involving temperature) * V1/T1 = V2/T2 For Changes in Pressure * P/T (initial) = P/T (final) * Example (LOOK IN NOTES ) * Avogadros Law nT * The volume of a brag is directly proportional to the quantity of bollocks, provided the pressure and temperature of the turgidness dont change. (V=Kn) * For changes in volume (involving moles) * V1/n1 = V2/n2 * Example (LOOK IN NOTES ) * Ideal Gas Laws * pV=nRT * NEED TO KNOW THIS formulation * P = pressure (atm) * V = volume (L) * n = quantity (moles) * T = temperature (K) * R = Universal Gas Constant * (0. 08206 Latm/molK) OR * (8. 314 J/molK) * Example (look in notes ) Density calculations * Density of a gas s.t.p. * For an Ideal gas STP, the molar volume = 22. 7 L * Density = mass/volume = mass/1mole = molar mass/molar volum * volume/1mole * Density for a gas NOT STP * If gas isnt at stp * then(prenominal) D = P(MM)/ RT or D = m/v * Molar Mass calculations * From the equations pV = mRT/MM You get MM = mRT/ pV * Example (Look in notes ) * Molar Volume * At STP, all perfect gases scoop out up the resembling volume. * Molar Volume = of L of gas 1 mole of gas This as well works V/n = RT/P * Partial Pressures Daltons Law of Partial Pressures * The come in pressure of a commixture of gases is the sum of the pressures by each gas. * The pressure of a gas would exert if it were alone in a container. * You can calculate the Partial Pressure from Ideal gas Law * If 2 gases , A and B are mixed together * P(A) = (nA)(R)(T)/ (V) and P(B) = (nB)(R)(T)/ (V) * Since R, T, and V are all constant for a mixture * P(total) = P(A) + P(B) = (nTotal)(R)(T)/ (V) * nTotal = sum of nA + nB * Example (Look in notes ) Eudiometer calculations * An Eudiometer is a gas comp overthrowium Tube * Example 2Zn (s) + 6HCl (aq) 3H2 (g) + 2ZnCl3 (aq) H20 (l) H2O (g) P(total) = P(H2) + P(H20) (value may be looked up at table 5. 4) * 0. 12 moles of Hz is collected over H20 in a total 10. 0 L container at 323 K. Find the total pressure. P = nRT/V P(H2) = (0. 12 mol H2) (0. 08206 Latm/molK) (323 K)= 0. 3181 am (10. 0L) P(total) = P(H2) + P(H20) P(H2O) 50 degrees Celsius = 92. 6 mmHg P(total) = 240mmHg + 96. 6mmHg = 330mmHg * Gas Reaction Stoichiometry * General Concept intention on most problems P, V, T of Gas A Amount A (in moles) Amount B (in moles) P, V, T of Gas B * Volume moles conversions * Ex Methanol CH3OH can be synthesized by the following reaction * CO2 (g) + 2H2(g) CH3OH(g) * What is the volume (in liters) of hydrogen gas a temperature of 355 K and pressure of 738 mmHG, is needful to synthesize 35. 7 g of wood alcohol * Given 35. 7 g CH3OH temp 355 K pressure 738 mmHG * Find V of H2 * 1. G of CH3OH mols * 35. 7g CH3OH x 1 mol CH3OH = 1. 1142 mol CH3OH 31. 04 g CH3OH * 2. Mol CH3OH mol H2 * 1. 11 mol CH3OH x 2 mols H2 = 2. 23 mols H2 1 mol CH3OH 3. N(mol H2), P, T VH2 * Convert your mmhg to ATM, and get . 971 atm * VH2= (2. 23 mol H2) (. 08206 l atm/ mol K) (355 K) = 66. 9 L .971 atm * VH2= 66. 9 L * Kinetic Molecular Theory * In this conjecture a gas is modeled as a accretion of particles (either molecules or atoms depending on the gas ) in constant motion. * Ex, a single particle moves in a substantial quarter until it collides with another particle (or with the walls of its container). * 4 components of the theory 1. Particles are infinitely small and have no volume 2. Average kinetic capacity of a particle is proportional to the temperature (k). . Particles travel in both straight lines following Newtonian Laws 4. All collisions are elastic (no deplumeive or raunchy forces) * You DO NOT need to know the derivation of I. G. L. * Effusion of Gases * Effusion the act upon by which a gas escapes from a container into a vacuum through a small hole. * The rate of effusion (the amount of gas that effuses in an amount of time) is also related to the root mean unbent velocit y * Rate is ? 1M * Grahms law of effusion * The ratio of effusion rates of deuce different gases. * For example (look in notes, end of chapter 5) Real Gases * van der Waals equation is an equation used to correct for the discrepancies from the Kinetic Molecular Theory that veridical gases undergo. Real gases attract each other, and then, real pressure high-flown pressure. Real gases also take up space, therefore, real volume ideal volume. P + a (n/v)? x (V nb) = nRT where a corrects for molecular interaction. It makes the real pressure larger so it contacts the ideal pressure b corrects for molecular size. It decreases the volume of the container. * Your extra credit question will have to do with this topic * Atmospheric Chemistry 3 types of pollution-very, very base question * 3 types of pollution-very, very basic question 1. Hydrocarbon combustion for automobiles 2C8H18 + 2SO2 > 16CO2 + 18 H2O At high temperature, nitrogen can also be combusted, which causes a problem . N2 + O2 > 2NO 2NO + O2 > 2NO2 (nitrogen dioxide) photochemical smog (causes problem in the environment) 2. burning at the stake of coal from power plants (Ex. Electrical cars) C + O2 > CO2 (Coal contains a significant amount of sulfur and it further combusts) S8 + 8O2 > 2SO3 2SO2 + O2 > 2SO3 SO3 + H2O > H2SO4 (H2SO4 results to acidification)But, spate have found a way to eliminate the production of SO3 and that is by utilise clean coal and scrubbers. CaCO3 + SO2 > CaO + CO2 CaO + SO2 > CaSO3 (s) (calcium sulfite) 3. Stratospheric Ozone O3 + UV > O2 + O (oxygen radical) O2 + O > O3 + IR These dickens equations above undecomposed shows how ozone is used and how it is just regenerated again. But, in 1974, Sherwood Rowland discovered that CFCs from air conditioners, refrigerators, and sprinkle cans destroy the atmospheric ozone. CF2Cl2 + UV > CF2Cl + Cl (chlorine radical) Cl + O3 + UV > O2 + ClO ClO + O > O2 + Cl ( 1 Cl radical can destroy a hundred th ousands of ozone) coiffure testanswer keyChapter 6 Thermochemistry * record of Energy * System versus Surroundings System the part of the universe we want to center on (like a chemical reaction inside a beaker) Surrounding everything else in the universe (like the glass of the beaker and the air some it) * Definition of Energy, internal energy, law of conservation of energy Energy is classified into two types a. light up (q) energy transferred that causes a temperature change (due to a change in the haphazard motion of molecules) b. work (w) energy transferred that causes an disapprove to move (due to a change in the concerted motion of the molecules in the object) c. nits of energy I. Joule (J) the amount of energy it take to move 1kg mass a length of 1 meter (unit kg*m2/s2) II. kilogram calorie (cal) the amount of energy needed to call forth the temperature of 1 gram of water by 1 ? C 1 kcal = 1000 cal (food calories) 1 cal = 4. 184 J (exact measurement) Internal E nergy total energy of a scheme. (Esystem) Law of conservation of energy energy is incomplete created or destroyed, only transferred. * 1st Law of Thermodynamics The change in energy of a system is equal to lovingness that enters the system plus the work do on the system. * ? E = q + w a. ?E = change in the internal energy of a system E is (+) if the energy is negligent by the system ?E is (-) if the energy is released by the system b. q = light q is (+) if the heat is put one acrossed by the system q is (-) if the heat is released by the system c. w = work w is (+) if the work is done on the system w is (-) if the work is done by the system on the ring * Heat and work * pV work is delineate by the equation w = -p? V * m Cs ? T heat transfer q = m Cs ? T where m = mass Cs = specific heat capacity (J/ g ? C) ?T = (Tfinal Tinitial) q = n Cm ? T where n = number of moles Cm = molar heat capacity (J/ mol ? C) ?T = (Tfinal Tinitial) conservation of thermal energy the amo unt of energy that is given must be equal with opposite sign to that energy that is being taken. qsurr = (qsys) msurr Cs(surr) ? T(surr) = -msys Cs(sys) ? Tsys * Calorimetry * Constant volume calorimetry * Constant volume calorimetry bomb calorimetry, no pv work done, therefore only heat contributes to ? E qcal = Ccal ? T = -qrxn where Ccal = calorimeter constant (KJ/ ? C) * * only heat contributes to ? E * Enthalpy * Definition, equation Enthalpy (? H) the heat absorbed or released during a mold taking place at a constant external pressure. ?H = qrxn = -qsurr ?H = -( m Cs ? T) Calculation using constant pressure calorimetry refer to example in notes * Exothermic versus Endothermic reactions (sign of ? H) Endothermic reactions have (+) ? H because they are reactions that absorb heat. Exothermic reactions have (-) ? H because they are reactions that give off heat. * Hesss Law * Enthalpy of reactions manipulations 2 rules to remember 1. If a reaction is reversed, the sign of ? H flips (from negative to positive or from positive to negative) 2. If you multiply coefficients by a number, ? H is also compute by that number. * This is a hard topic, please, please, please review this after Wednesday