Q&A Hero

Q: The standard free energy change for a chemical reaction is +13.3 kJ/mol. What is the equilibrium constant for the reaction at 125 C? (R = 8.314 J/Kmol)A.2.8 10-6B.2.0 10-5C.4.7 10-3D.1.8 10-2E.2.1 102

Q: For a chemical system, DrG and DrG are equal when A.the system is in equilibrium. B.the reactants and products are in standard state conditions. C.the equilibrium constant, K, equals 0. D.the reaction quotient, Q, is less than 1. E.the reactants and products are in the gas phase.

Q: All of the following relationships are true EXCEPT A.. B.. C.. D.. E..

Q: For a chemical reaction, if DrG = 0, then ____.A.K > 1B.K = 0C.K = -1D.K < 0E.K = 1

Q: Thermodynamics can be used to determine all of the following EXCEPT A.the temperature at which a reaction is spontaneous. B.the extent to which a reaction occurs. C.the direction in which a reaction is spontaneous. D.the rate of reaction. E.the entropy change of a reaction.

Q: Estimate the boiling point of ethanol given the following thermodynamic parameters.C2H5OH() C2H5OH(g)DfH (kJ/mol) -277.0 -235.3S (J/Kmol) 160.7 282.7DfG (kJ/mol) -174.7 -168.5A.22 CB.44 CC.61 CD.69 CE.91 C

Q: Given thatS(g) + O2(g) SO2(g) DrG = -300.1 kJ/mol-rxn2 S(g) + 3 O2(g) 2 SO3(g) DrG = -742.1 kJ/mol-rxncalculate DfG of the following reaction:SO2(g) + 1/2 O2(g) SO3(g)A.-1042.2 kJ/mol-rxnB.-71.0 kJ/mol-rxnC.+2.47 kJ/mol-rxnD.+71.0 kJ/mol-rxnE.+1042.2 kJ/mol-rxn

Q: At 298.15 K, all of the following substances have a standard free energy of formation of zero EXCEPT ____. A.Br2(g) B.I2(s) C.S8(s) D.Cl2(g) E.Hg()

Q: Calculate DrG for the combustion of benzene at 325 K.2 C6H6() + 15 O2(g) 12 CO2(g) + 6 H2O()Species DfH (kJ/mol) S (J/Kmol)C6H6() 49.0 173.3O2(g) 0 205.1CO2(g) -393.5 213.7H2O() -285.8 67.0A.-6386 kJ/mol-rxnB.-6078 kJ/mol-rxnC.-7251 kJ/mol-rxnD.-8611 kJ/mol-rxnE.+1431 kJ/mol-rxn

Q: Calculate DrG for the reaction below at 25.0 C.P4O10(s) + 6 H2O() 4 H3PO4()Species DfH (kJ/mol) S (J/K mol)P4O10(s) -2984.0 228.9H2O() -285.8 69.95H3PO4() -1279.0 110.5A.-6119.1 kJ/mol-rxnB.-632.8 kJ/mol-rxnC.-355.6 kJ/mol-rxnD.+210.6 kJ/mol-rxnE.+6119.1 kJ/mol-rxn

Q: The DrG for the following reaction is -100.4 kJ.C2H4(g) + H2(g) C2H6(g)Given DfG [C2H4(g)] = +68.4 kJ/mol, calculate DfG [C2H6(g)].A.-168.8 kJ/mol-rxnB.-32.0 kJ/mol-rxnC.+1.486 kJ/mol-rxnD.+32.0 kJ/mol-rxnE.+168.8 kJ/mol-rxn

Q: Calculate DrG for the reaction below at 25.0 CCH4(g) + H2O(g) 3 H2(g) + CO(g)given DfG [CH4(g)] = -50.8 kJ/mol, DfG [H2O(g)] = -228.6 kJ/mol, DfG [H2(g)] = 0.0 kJ/mol, and DfG [CO(g)] = -137.2 kJ/mol.A.-416.3 kJ/mol-rxnB.-142.2 kJ/mol-rxnC.+142.2 kJ/mol-rxnD.+315.0 kJ/mol-rxnE.+416.3 kJ/mol-rxn

Q: Calculate DrG for the reaction below at 25.0 C2 Na(s) + 2 H2O() 2 NaOH(aq) + H2(g)given DrH = -366.6 kJ/mol-rxn and DrS = -154.2 J/Kmol-rxn.A.-371.2 kJ/mol-rxnB.-320.6 kJ/mol-rxnC.-215.4 kJ/mol-rxnD.+371.2 kJ/mol-rxnE.+4634.9 kJ/mol-rxn

Q: Calculate DrG for the reaction below at 25.0 CCS2(g) + 3 Cl2(g) S2Cl2(g) + CCl4(g)given DrH = -231.1 kJ/mol-rxn and DrS = -287.6 J/Kmol-rxn.A.-518.7 kJ/mol-rxnB.-316.9 kJ/mol-rxnC.-145.3 kJ/mol-rxnD.-56.5 kJ/mol-rxnE.+56.5 kJ/mol-rxn

Q: If a chemical reaction is exothermic, but not spontaneous, which of the following must be true? A.DrG > 0, DrS > 0 and DrH > 0 B.DrG < 0, DrS > 0 and DrH > 0 C.DrG > 0, DrS < 0 and DrH > 0 D.DrG < 0, DrS < 0 and DrH < 0 E.DrG > 0, DrS < 0 and DrH < 0

Q: For a reaction, DrH = -208.8 kJ and DrS = -308.2 J/K. At what temperature will DrG = 0.00 kJ?A.0.68 KB.677.5 KC.1476 KD.6435 KE.DG is less than 0.00 kJ at any temperature.

Q: At what temperatures will a reaction be spontaneous if DrH = +117 kJ and DrS = -35 J/K?A.All temperatures below 94.1 KB.Temperatures between 12.7 K and 135 KC.All temperatures above 94.1 KD.The reaction will be spontaneous at any temperature.E.The reaction will never be spontaneous.

Q: At what temperatures will a reaction be spontaneous if DrH = +62.4 kJ and DrS = +301 J/K? A.All temperatures below 207 K. B.All temperatures above 207 K. C.Temperatures between 179 K and 235 K. D.The reaction will be spontaneous at any temperature. E.The reaction will never be spontaneous.

Q: If a cube of ice at 0 C is placed outside on a warm summer day, the ice will melt spontaneously. What are the signs of DrH, DrS, and DrG for this process? A.DrH < 0, DrS > 0, DrG < 0 B.DrH < 0, DrS < 0, DrG < 0 C.DrH < 0, DrS > 0, DrG > 0 D.DrH > 0, DrS > 0, DrG < 0 E.DrH > 0, DrS < 0, DrG > 0

Q: Diluting concentrated sulfuric acid with water can be dangerous. The temperature of the solution can increase rapidly. What are the signs of DrH, DrS, and DrG for this process? A.DrH < 0, DrS > 0, DrG < 0 B.DrH < 0, DrS < 0, DrG < 0 C.DrH < 0, DrS > 0, DrG > 0 D.DrH > 0, DrS > 0, DrG < 0 E.DrH > 0, DrS < 0, DrG > 0

Q: The dissolution of ammonium nitrate occurs spontaneously in water at 25 C. As NH4NO3 dissolves, the temperature of the water decreases. What are the signs of DrH, DrS, and DrG for this process? A.DrH > 0, DrS < 0, DrG > 0 B.DrH > 0, DrS > 0, DrG > 0 C.DrH > 0, DrS > 0, DrG < 0 D.DrH < 0, DrS < 0, DrG < 0 E.DrH < 0, DrS > 0, DrG > 0

Q: If DrG > 0 for a reaction at all temperatures, then DrH is ____ and DrS is ____. A.negative, positive B.positive, negative C.negative, negative D.positive, positive E.positive, either positive or negative

Q: Hydrogen gas is a non-polluting fuel. Hydrogen gas may be prepared by electrolysis of water. 2 H2O() 2 H2(g) + O2(g) Predict the signs of DrH and DrS for the production of hydrogen gas by electrolysis of water. A.DrH > 0 and DrS > 0 B.DrH < 0 and DrS > 0 C.DrH > 0 and DrS < 0 D.DrH < 0 and DrS < 0 E.DrH = 0 and DrS < 0

Q: When a real gas is compressed from low pressure to a higher pressure, its temperature increases. Predict the signs of of DH and DS. A.DH < 0 and DS < 0 B.DH < 0 and DS > 0 C.DH > 0 and DS < 0 D.DH > 0 and DS > 0 E.DH < 0 and DS = 0

Q: Use the following thermodynamic data.Species DfH (kJ/mol) S (J/Kmol)Fe(s) 0.0 27.8O2(g) 0.0 205.1Fe3O4(s) -1118.4 146.4to calculate DS (universe) for the formation of Fe2O3(s) at 298.15 K.3 Fe(s) + 2 O2(g) Fe3O4(s)A.-3404 J/KB.-1162 J/KC.+561.2 J/KD.+3404 J/KE.+7639 J/K

Q: For the combustion of acetylene at 298.15 K,2 C2H2(g) + 5 O2(g) 4 CO2(g) + 2 H2O(g)calculate DS(universe) given DS(system) = -194.6 J/K and DH(system) = -2511.2 kJ.A.-2453.2 J/KB.-186.2 J/KC.+186.2 J/KD.+1290.4 J/KE.+8228.0 J/K

Q: The standard entropy for the formation of SF6(g) from the elements,S(s) + 3 F2(g) SF6(g)is -348.7 J/Kmol at 298.15 K. Calculate the standard molar entropy of SF6(g) given S[S(s)] = 32.1 J/Kmol and S[F2(g)] = 202.8 J/Kmol.A.-988.6 J/KmolB.+291.8 J/KmolC.-291.8 J/KmolD.-113.2 J/KmolE.+113.8 J/Kmol

Q: Calculate the standard entropy change for the following reaction,2 SO2(g) + O2(g) 2 SO3(g)given S[SO2(g)] = 248.2 J/Kmol-rxn, S[O2(g)] = 205.1 J/Kmol-rxn, and S[SO3(g)] = 256.8 J/Kmol-rxn.A.-196.5 J/KB.-94.0 J/KC.-187.9 J/KD.+187.9 J/KE.+196.5 J/K

Q: Calculate the standard entropy change for the combustion of ethanol at 25 C.CH3CH2OH() + 3 O2(g) 2 CO2(g) + 3 H2O(g)Species S (J/Kmol)CH3CH2OH() 160.7O2(g) 205.1CO2(g) 213.7H2O(g) 188.8A.-35.9 J/KB.+35.9 J/KC.+217.8 J/KD.+422.9 J/KE.+833.1 J/K

Q: For which of the following reactions will the entropy of the system decrease?A.2 NH3(g) N2(g) + 3 H2(g)B.2 C(s) + O2(g) 2 CO(g)C.CaCO3(s) CaO(s) + CO2(g)D.2 NO2(g) N2O4(g)E.NaOH(s) Na+(aq) + OH-(aq)

Q: All of the following processes lead to an increase in entropy EXCEPT A.decreasing the volume of a gas. B.melting a solid. C.chemical reactions that increase the number of moles of gas. D.forming mixtures from pure substances. E.increasing the temperature of a gas.

Q: Which one of the following processes involves an increase in the entropy of the system? A.3 H2(g) + N2(g) 2 NH3(g) B.N2(g) + 2 O2(g) 2 NO2(g) C.2 Ag2O(s) 4 Ag(s) + O2(g) D.CaO(s) + CO2(g) CaCO3(s) E.2 Na(s) + Cl2(g) 2 NaCl(s)

Q: If a chemical reaction occurs in a direction that has a positive change in entropy then A.the change in enthalpy must be negative. B.the reaction must be spontaneous. C.heat goes from the system into the surroundings. D.the reaction must be exothermic. E.the disorder of the system increases.

Q: Which of the following linear chain alcohols is likely to have the highest standard entropy in the liquid state? A.CH3OH B.CH3CH2OH C.CH3CH2CH2OH D.CH3CH2CH2CH2OH E.CH3CH2CH2CH2CH2OH

Q: Which of the following statements concerning entropy is/are CORRECT? 1/ The entropy of a substance increases when converted from a liquid to a solid. 2/ The entropy of a substance decreases as its temperature increases. 3/ All substances have positive entropy values at temperatures above 0 K. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: As defined by Ludwig Boltzmann, the third law of thermodynamics states that A.there is no disorder in a perfect crystal at 0 K. B.in a spontaneous process, the entropy of the universe increases. C.the total entropy of the universe is always increasing. D.the total mass of the universe is constant. E.mass and energy are conserved in all chemical reactions.

Q: The second law of thermodynamics states that A.in a spontaneous process, the entropy of the universe increases. B.there is no disorder in a perfect crystal at 0 K. C.the total energy of the universe is always increasing. D.the total energy of the universe is constant. E.mass and energy are conserved in all chemical reactions.

Q: A statement of the first law of thermodynamics is that A.in a spontaneous process, the entropy of the universe increases. B.there is no disorder in a perfect crystal at 0 K. C.the total energy of the universe is always decreasing. D.the total energy of the universe is constant. E.mass and energy are conserved in all chemical reactions.

Q: Which of the following statements is/are CORRECT? 1/ Spontaneous changes only occur in the direction that leads to equilibrium. 2/ Exothermic reactions are always spontaneous. 3/ In any chemical reaction, energy must be conserved. A.1 only B.2 only C.3 only D.1 and 3 E.1, 2, and 3

Q: The following processes occur spontaneously at 25 C. Which of these processes is/are endothermic? 1/ NH4NO3 dissolving in water (which is accompanied by a cooling of the water). 2/ the expansion of a real gas into a vacuum (which is accompanied by a cooling of the gas). 3/ liquid water in an ice cube tray freezing into ice after being placed in a freezer. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: When a chemical process occurs under standard conditions, which of the following conditions always apply? 1/ Gaseous species are at a pressure of 1 bar. 2/ Solution concentrations species are 1 molal. 3/ The temperature is 298.15 K. A.1 only B.2 only C.3 only D.1 and 2 E.1, 2, and 3

Q: Use the standard entropies for liquid water and steam to estimate the enthalpy of vaporization of water at its normal boiling point. DS [H2O()] = 69.9 J/Kmol and DS [H2O(g)] = 188.8 J/Kmol.

Q: Does the formation of complex molecules such as proteins and nucleic acids from more simple molecules contradict the second law of thermodynamics?

Q: At what temperature (in kelvin units) is the entropy of a pure crystal 0.0 J/K.

Q: For any process, the change in entropy of the universe equals the sum of the entropy changes for the system and for the ________.

Q: The change in entropy for any process is not dependent upon the pathway by which the process occurs. In other words, the change in entropy for any process is a(n) ________ function.

Q: ________ changes only occur in the direction that leads toward chemical equilibrium.

Q: The total entropy of the universe is always increasing. This is a statement of the ________ law of thermodynamics.

Q: Why do salts containing basic anions have a greater solubility in water than predicted from calculations using Ksp values?

Q: Hyperventilation can cause your blood pH to rise. One way to lower your blood pH is to breath into a paper bag, thus recycling the air you exhale. Why does this procedure lower your blood pH?

Q: To make a buffer with a pH of 8.00, you should use a weak acid with a Ka close to _______.

Q: If the ratio of acid to base in a buffer is increased by a factor of 10, the buffer pH decreases by ________.

Q: For a monoprotic acid titration, the ________ point in a titration is the point where the moles of strong base added equals the moles of acid initially present.

Q: Two important biological buffer systems control pH in the range between 6.9 and 7.4. These buffer systems are H2CO3/HCO3- and ________.

Q: Given the following reactions,AgBr(s) Ag+(aq) + Br-(aq) Ksp = 5.4 10-13Ag+(aq) + 2 CN-(aq) Ag(CN)2-(aq) Kf = 1.2 1021determine the equilibrium constant for the reaction below.AgBr(s) + 2 CN-(aq) Ag(CN)2-(aq) + Br-(aq)A.4.5 10-34B.1.5 10-9C.6.5 108D.1.2 1021E.2.2 1033

Q: Consider the reactionCu2+(aq) + 4 NH3(aq) Cu(NH3)42+(aq) Kf = 2.1 1013If Ksp for Cu(OH)2 is 2.2 10-20, what is the value of the equilibrium constant, K, for the reaction below?Cu(NH3)42+(aq) + 2 OH-(aq) Cu(OH)2(s) + 4 NH3(aq)A.1.0 10-33B.4.6 10-7C.2.1 1013D.2.2 106E.9.5 1032

Q: The following anions can be separated by precipitation as silver salts: Cl-, Br-, I-, CrO42-. If Ag+ is added to a solution containing the four anions, each at a concentration of 0.10 M, in what order will they precipitate?Compound KspAgCl 1.8 10-10Ag2CrO4 1.1 10-12AgBr 5.4 10-13AgI 8.5 10-17A.AgCl Ag2CrO4 AgBr AgIB.AgI AgBr Ag2CrO4 AgClC.Ag2CrO4 AgCl AgBr AgID.Ag2CrO4 AgI AgBr AgClE.AgI AgBr AgCl Ag2CrO4

Q: An aqueous solution contains 0.010 M Br- and 0.010 M I-. If Ag+ is added until AgBr(s) just begins to precipitate, what are the concentrations of Ag+ and I-? (Ksp of AgBr = 5.4 10-13, Ksp of AgI = 8.5 10-17)A.[Ag+] = 5.4 10-11 M, [I-] = 1.0 10-2 MB.[Ag+] = 8.5 10-15 M, [I-] = 1.0 10-2 MC.[Ag+] = 5.4 10-11 M, [I-] = 1.6 10-6 MD.[Ag+] = 8.5 10-15 M, [I-] = 6.4 101 ME.[Ag+] = 8.5 10-15 M, [I-] = 1.6 10-6 M

Q: What mass of KCl (molar mass = 74.55 g/mol) must be added to 1.0 L of 0.0180 M Pb2+(aq) to initiate precipitation of PbCl2(s)? The Ksp of PbCl2 is 1.7 10-5. Assume no volume change occurs upon addition of KCl.A.6.6 10-5 gB.0.041 gC.0.070 gD.2.3 gE.2.5 g

Q: The concentration of Pb2+ in an aqueous solution is 5.5 10-3 M. What concentration of SO42- is required to begin precipitating PbSO4? The Ksp of PbSO4 is 2.5 10-8.A.1.4 10-10 MB.4.5 10-6 MC.1.6 10-4 MD.8.3 10-4 ME.2.9 10-2 M

Q: At what pH will an aqueous solution of 0.200 M Ni2+ begin to precipitate as Ni(OH)2 at 25 C? The Ksp of Ni(OH)2 is 5.5 10-16 at 25 C.A.6.37B.6.72C.7.28D.7.63E.7.93

Q: What is the molar solubility of Mn(OH)2(s) in a solution that is buffered at pH 8.00 at 25 C? The Ksp of Mn(OH)2 is 1.9 10-13 at 25 C.A.3.6 10-8 mol/LB.1.9 10-7 mol/LC.3.6 10-5 mol/LD.1.9 10-1 mol/LE.1.9 103 mol/L

Q: What is the molar solubility of Fe(OH)3(s) in a solution that is buffered at pH 2.50 at 25 C? The Ksp of Fe(OH)3 is 6.3 10-38 at 25 C.A.6.9 10-28 mol/LB.2.0 10-26 mol/LC.1.3 10-13 mol/LD.2.0 10-3 mol/LE.5.0 102 mol/L

Q: What is the molar solubility of BaF2 in 0.033 M KF(aq) at 25 C? The value of Ksp of BaF2 is 1.8 10-7 at 25 C.A.2.7 10-6 mol/LB.5.5 10-6 mol/LC.4.1 10-5 mol/LD.1.1 10-4 mol/LE.1.7 10-4 mol/L

Q: The Ksp of AgI is 8.5 10-17 at 25 C. Calculate the molar solubility of AgI in 0.0045 M KI(aq) at 25 C.A.1.9 10-14 mol/LB.3.8 10-12 mol/LC.9.2 10-9 mol/LD.1.4 10-7 mol/LE.2.0 10-6 mol/L

Q: The Ksp of BaSO4 is 1.1 10-10 at 25 C. What mass of BaSO4 (molar mass = 233.4 g/mol) will dissolve in 1.0 L of water at 25 C?A.2.6 10-8 gB.4.5 10-8 gC.1.0 10-5 gD.1.6 10-4 gE.2.4 10-3 g

Q: The Ksp of Ca(OH)2 is 5.5 10-5 at 25 C. What is the concentration of OH-(aq) in a saturated solution of Ca(OH)2(aq)?A.1.9 10-3 MB.7.4 10-3 MC.2.4 10-2 MD.4.0 10-2 ME.4.8 10-2 M

Q: The solubility of PbI2 in water is 0.62 g in 1.0 L of water at 25 C. What is the value of Ksp for PbI2?A.8.4 10-10B.2.4 10-9C.9.7 10-9D.1.8 10-6E.0.95

Q: The solubility of BaCrO4(s) in water is 3.7 milligrams in 1.0 L at 25 C. What is the value of Ksp for BaCrO4?A.2.1 10-10B.8.6 10-10C.1.4 10-5D.1.5 10-5E.2.9 10-5

Q: Which of the following equations is the solubility product for Cu(II) hydroxide, Cu(OH)2? A. B. C. D. E.

Q: What color change is exhibited by phenolphthalein during a titration of aqueous acetic acid with aqueous sodium hydroxide? A.colorless to pink B.pink to colorless C.green to yellow D.yellow to blue E.blue to yellow

Q: Which is the best colored indicator to use in the titration of 0.1 M CH3CO2H(aq) with NaOH(aq)? Why? (Ka of CH3CO2H = 1.8 10-5, Kb of CH3CO2- = 5.6 10-10)Indicator pKaBromcresol Green 4.8Bromthymol Blue 6.8Phenolphthalein 9.2A.Bromcresol Green. The equivalence point for a weak acid titration occurs at low pH.B.Bromthymol Blue. The pH at the equivalence point is 7.0.C.Bromcresol Green. The pKa of CH3CO2H and the pKa of the indicator are similar.D.Phenolphthalein. The pKa of CH3CO2- and the pKb of the indicator are similar.E.Phenolphthalein. The pH at the equivalence point is near the pKa of the indicator.

Q: An impure sample of sodium carbonate, Na2CO3, is titrated with 0.113 M HCl according to the reaction below. 2 HCl(aq) + Na2CO3(aq) CO2(g) + H2O() + 2 NaCl(aq) What is the percent of Na2CO3 in a 0.613 g sample if the titration requires 26.14 mL of HCl? The molar mass of Na2CO3 is 106.0 g/mol. A.0.295% B.15.7% C.25.5% D.51.1% E.67.9%

Q: A 30.00 mL sample of vinegar is titrated with 0.4190 M NaOH(aq). If the titration requires 27.83 mL of NaOH(aq), what is the concentration of acetic acid in the vinegar? A.0.1931 M B.0.2016 M C.0.2174 M D.0.3887 M E.0.4517 M

Q: Potassium hydrogen phthalate (KHP) is used to standardize sodium hydroxide. If 35.39 mL of NaOH(aq) is required to titrate 0.8246 g KHP to the equivalence point, what is the concentration of the NaOH(aq)? (The molar mass of KHP = 204.2 g/mol)HC8H4O4-(aq) + OH-(aq) C8H4O42-(aq) + H2O()A.0.02318 MB.0.05705 MC.0.0859 MD.0.1141 ME.0.1429 M

Q: A 25.0 mL sample of 0.10 M sodium benzoate is titrated with 0.10 M HCl(aq). What is the pH after the addition of 32.0 mL of HCl(aq)? (Kb of C6H5CO2- = 1.6 10-10)A.1.00B.1.25C.1.91D.4.20E.9.79

Q: A 25.0 mL sample of 0.200 M HCO2H(aq) is titrated with 0.100 M KOH(aq). What is the pH at the equivalence point? (Ka of HCO2H = 1.8 10-4)A.5.71B.7.00C.8.28D.8.52E.10.26

Q: A 25.0 mL sample of 0.400 M NH3(aq) is titrated with 0.400 M HCl(aq). What is the pH at the equivalence point? (Kb of NH3 = 1.8 10-5)A.2.72B.4.97C.7.00D.9.03E.11.28

Q: A 50.0 mL sample of 0.155 M HNO2(aq) is titrated with 0.100 M NaOH(aq). What is the pH of a solution after the addition of 25.0 mL of NaOH? (Ka of HNO2 = 4.5 10-4)A.3.02B.3.22C.3.67D.3.86E.4.05

Q: A volume of 25.0 mL of 0.100 M C6H5CO2H(aq) is titrated with 0.100 M NaOH(aq). What is the pH after the addition of 12.5 mL of NaOH? (Ka of benzoic acid = 6.3 10-5)A.2.60B.4.20C.5.40D.7.00E.8.60