1.I. Heat is released with an endothermic reaction 4.I. The

A) I is TRUE, II is FALSEB) I is FALSE, II is TRUEC) I and II are BOTH FALSED) I and II are BOTH TRUE but II IS NOT a correct

explanation of IE) I and II are BOTH TRUE and II IS a correct

explanation of I

1. I. Heat is released with an endothermic reaction

BECAUSE

II. energy is released when bonds are formed.

A) I is TRUE, II is FALSEB) I is FALSE, II is TRUEC) I and II are BOTH FALSED) I and II are BOTH TRUE but II IS NOT a

correct explanation of IE) I and II are BOTH TRUE and II IS a correct

explanation of I

2. I. When hydrochloric acid and water are mixed to form asolution, the entropy increases

BECAUSE

II. energy is released.



explanation of I

3. I. Steam condenses to water and releases heat

BECAUSE

II. the temperature remains constant during a phasechange.



explanation of I

4. I. The heat of fusion of ice is greater than the heat ofvaporization of water

BECAUSE

II. stronger hydrogen bonds are broken when ice ischanged into water than when water is changed intostream.



explanation of I

5. I. The solubility of solids in water increases with anincrease in temperature

BECAUSE

II. the entropy increases.



explanation of I

6. I. An exothermic reaction always has a negative G

BECAUSE

II. heat is released when the reaction occurs.



explanation of I

7. I. An endothermic reaction always has a positive G

BECAUSE

II. heat is released when the reaction occurs.



explanation of I

8. I. A positive DS represents a decrease in potential energy

BECAUSE

II. DS represents the difference in the entropy of theproducts and the reactants.



explanation of I

9. I. A positive DS tells you that the reaction must bespontaneous

BECAUSE

II. entropy always increases when a reaction occurs.



explanation of I

10. I. A positive DH tells you that the reaction isexothermic

BECAUSE

II. with a positive DH, the products have more energythan the reactants.



explanation of I

11. I. The activation energy of an exothermic reaction isalways less than that of the reverse reaction

BECAUSE

II. the products have more energy than the reactants.



explanation of I

12. I. When propane is burned in air, energy is absorbed

BECAUSE

II. the reaction is exothermic.



explanation of I

13. I. When N2(g) is heated, its potential energy increases

BECAUSE

II. temperature is a measure of average potentialenergy.

A) 0.34 cal B) 3.0 calC) 4.7 cal D) 157.3 calE) 189.6 cal

14. If the specific heat capacity of a metal is .79 cal/g °Cand an 8 gram block of the metal is heated so that thetemperature of the block is increased by 30°C, howmuch energy did the metal absorb?

A) 0.68 g B) 5.95 gC) 16.8 g D) 37.3 gE) 81.4 g

15. A beaker of water is heated for ten minutes. If the waterabsorbs 370 calories and its temperature is raised from25°C to 47°C, what is the mass of water contained inthe beaker?

A) 55.0 cal B) 60.5 calC) 550.0 cal D) 605.0 calE) 760.0 cal

16. 10 grams of a metal with a specific heat capacity of1.10 cal/g °C are heated over a bunsen burner. If thetemperature of the metal increases by 55°C, how muchenergy did the metal absorb?

A) 3.1 g B) 5.2 gC) 10.8 g D) 15.4 gE) 40.6 g

17. The specific heat of a metal is .58 cal/g °C. If a sampleof this metal absorbs 250 calories and its temperatureincreases from 12°C to 40°C, what is the mass of thesample?

A) .05 °C/(cal g) B) .05 cal/(g °C)C) 0.5 °C/(cal g) D) 0.5 cal/(g °C)E) 5.0 °C/(cal g)

18. If the temperature of a 2 gram block of metal increasesby 10°C over the course of 30 minutes, and during thattime the block absorbs 100 calories from theenvironment, what is the specific heat of the metal?

A) HF B) HCl C) HBr D) HI E) HAt19. Which would have the highest heat of fusion?

A) H2O B) CO2 C) MgO D) Li2O E) NaCl20. Which would have the lowest heat of fusion?

21. Lead, PbMM = 207.2Heat of Fusion = 4.77 kJ•mol–1 Specific Heat = 0.134J•g–1•°C–1.

A) 2.30 kJ B) 32.4 kJC) 36.2 kJ D) 40.6 kJE) 50.8 kJ

How much heat is needed to convert 800. g of solidlead, Pb, at 25°C, to molten lead at its melting point,327°C?

22. Heat of Fusion of Water, H2O = 340 J•g–1

A) 5.7 × 10–3 g B) 1.7 × 102 gC) 5.8 × 104 g D) 3.5 × 105 gE) 2.0 × 107 g

What quantity of ice can be melted by 58,000 Joules?

23. Molar Heat Of Fusion of Water, H2O = 6.02 kJ•mol–1


How much energy is required to melt 14.0 g of water?

24. Molar Heat of Fusion of Water, H2O, is 6.02 kJ•mol–1

A) 2.01 kJ•mol–1 B) 6.02 kJ•mol–1C) 12.0 kJ•mol–1 D) 15.0 kJ•mol–1E) 18.1 kJ•mol–1

What is the energy required to melt 3.00 mol of ice?

A) HF B) HCl C) HBr D) HI E) H2S25. Which would have the highest heat of vaporization?

A) H2O B) CO2 C) MgO D) Li2O E) HF26. Which would have the lowest heat of vaporization?

27. Chloroform, CHCl3MM = 119.6Heat of Vaporization = 59.0 cal•g–1 1.000 cal = 4.184 J

A) 1.64 kJ B) 2.13 kJC) 29.5 kJ D) 59.0 kJE) 426 kJ

What is the heat of vaporization, Hvap, of CHCl3, in kJ•mol–1?

28. Acetone, (CH3)2COMM = 58.3Heat of Vaporization = 537 J•g–1

A) 23.3 g B) 43.0 gC) 537 g D) 860 gE) 12,500 g

What mass of acetone can be vaporized by theabsorption of 12.5 kJ of heat?

29. Ethyl alcohol, CH3CH2OHMM = 46.2Heat of Vaporization = 881 J•g–1

A) 0.881 kJ B) 1.10 kJC) 23.8 kJ D) 50.9 kJE) 110 kJ

How much heat is evolved when 1.25 kg of C2H5OH(g)condenses to C2H5OH(l) at its normal boiling point?

30. Diethyl ether, (CH3CH2)2OMM = 74.1Heat of Vaporization = 27.8 kJ•mol–1 Specific Heat =2.30 J•g–1•°C–1


How many kJ are needed to convert 100. g of liquiddiethyl ether, CH3CH2OCH2CH3 at 20°C, to gaseousdiethyl ether at its boiling point, 30°C?

31. Heat of Vaporization of Ethanol, CH3CH2OH = 880. J•g–1.

A) 557 J B) 673 JC) 880 J D) 1760 JE) 3360 J

How many Joules are needed to vaporize 2.00 g ofliquid ethanol, CH3CH2OH, at its boiling point, 78°C?

A) increases since energy is released by the reactionB) decreases since energy is released by the reactionC) increases since energy is absorbed by the reactionD) decreases since energy is absorbed by the

reactionE) remains the same

32. When an endothermic reaction occurs in a watersolution, the temperature of the solution

A) NH3(g) ® NH3(l) B) CO2(s) ® CO2(g)C) H2O(s) ® H2O(l) D) H2S(l) ® H2S(g)E) HF(l) ® HF(g)

33. Which phase change is exothermic?

A) crystallizing H2O(l) B) melting H2O(s)C) freezing H2O(l) D) condensing H2O(g)E) none of the above

34. Which phase change absorbs energy?

A) exothermic, with a release of energyB) endothermic, with a release of energyC) exothermic, with an absorption of energyD) endothermic, with an absorption of energyE) isothermic, with an increase in total energy

35. When a substance dissolves in water, the temperature ofthe water decreases. This process is

A) exothermic and evolves energyB) exothermic and absorbs energyC) endothermic and evolves energyD) endothermic and absorbs energyE) none of the above

36. When a mixture of barium hydroxide, Ba(OH)2, andammonium thiocyanate, NH4SCN, is mixed in a beaker,it gets so cold that a moistened block of wood freezesto the bottom of the beaker. This shows that thisreaction is

A) increases since energy is released by thereaction

B) decreases since energy is released by the reactionC) increases since energy is absorbed by the reactionD) decreases since energy is absorbed by the reactionE) remains the same

37. When an exothermic reaction occurs in a watersolution, the temperature of the solution

A) NH3(s) ® NH3(l) B) CO2(s) ® CO2(g)C) H2O(g) ® H2O(l) D) H2S(s) ® H2S(g)E) H2O(l) ® H2O(g)

38. Which phase change is exothermic?

A) boiling H2O(l) B) melting H2O(s)C) evaporating H2O(l) D) subliming H2O(s)E) condensing H2O(g)

39. Which phase change releases energy?

A) is exothermic, with a release of energyB) is endothermic, with a release of energyC) is exothermic, with an absorption of energyD) is endothermic, with an absorption of energyE) can be either exothermic or endothermic

40. When a substance dissolves in water, the temperature ofthe water increases. This process

A) exothermic and evolves energyB) exothermic and absorbs energyC) endothermic and evolves energyD) endothermic and absorbs energyE) none of the above

41. When sulfuric acid, H2SO4, is added to water in abeaker, the container and its contents get hot. Thisshows that the solution reaction is

42.

A) AB B) BC C) CD D) DE E) EF

During which segment of the graph is the potentialenergy change the greatest?

A) cooled as a gasB) cooled as a solidC) cooled as a liquidD) converted from a gas to a liquidE) converted from a liquid to a solid

43. The greatest reduction of the average potential energyof water molecules occurs when the water is

A) H2O(s)B) H2O(l)C) H2O(aq)D) H2O(g)E) The potential energies are equal.

44. Which water sample has the greatest potential energy?

A) the substance sublimesB) the volume is decreasedC) the pressure is increasedD) the substance condensesE) two different compounds are mixed together

45. A decrease in the potential energy of a molecule occursas

A) cooled as a gasB) cooled as a solidC) cooled as a liquidD) converted from a gas to a liquidE) converted from a liquid to a solid

46. The greatest reduction of the average kinetic energy ofwater molecules occurs when the water is

47.

A) PB) QC) RD) SE) It is impossible to determine from this diagram.

At which time is the kinetic energy highest?

A) total potential energyB) average kinetic energyC) average potential energyD) total kinetic energyE) kinetic and potential energy

48. The temperature of a sample of carbon dioxide gas is ameasure of its

A) B)

C) D)

49. Which illustrates the temperature–time graph for theheating of ice at –10° C to produce steam at 125°C?

A) °C = K + 273B) °C = K × 273

100C) °C = K × 100

273D) °C = K – 273E) °C = K + 273

100

50. Which formula is used to change a temperature readingfrom the Kelvin scale to the Celsius scale?

A) 0°CB) 0 KC) –273 KD) the temperature at which water freezesE) –273° F

51. The expression absolute zero refers to

52. Freezing PointsHg 234 KCd 594 K

A) 324 K B) 527 KC) 558 K D) 597 KE) 644 K

A temperature scale is devised using the freezing pointof mercury as 0°N and the freezing point of cadmiumas 100°N. How many Kelvins correspond to 90°N?

A) freezing waterB) burning magnesiumC) magnetizing ironD) liquefying oxygenE) breaking glass

53. Which is a chemical change?

54. Fifty grams (50.0 g) of water is heated from 18.0°C to32.0°C. How much heat is absorbed?

A) 2,930 J B) 3,770 JC) 5,230 J D) 5,960 JE) 6,690 J

A) 0 K B) 32 KC) 273 K D) 546 KE) 646 K

55. To what temperature in Kelvin does 273°C correspond?

A) always absorbedB) always releasedC) usually not involvedD) never conservedE) either absorbed or released

56. In any chemical reaction, energy is

57. How much heat is absorbed when 50.0 grams of wateris heated from 22.0°C to 36.0°C?

A) 1,510 J B) 2,930 JC) 4,520 J D) 7,530 JE) 15,060 J

A) 25°C B) 212°CC) 398°C D) 521°CE) 596°C

58. Which Celsius temperature is equivalent to 298 K?

A) a change in massB) no energy changesC) a change in densityD) a change in compositionE) a change in chemical properties

59. Water in changing from a solid to a gas through thethree physical states would normally undergo

A) Mg is less active than H2

B) Mg is more stable than Mg2+C) one mole of Mg reacts with one mole of H+

D) one mole of Mg liberates one mole of H2

E) Mg(s) reacts spontaneously with H2(g)

60. Mg(s) + 2 H+(aq) ® Mg2+(aq) + H2(g)The above equation shows that

61. Air pressure is graphed as a function of temperature.The extrapolated line intersects the horizontal axis atabout –280°C. Which term is applied to thistemperature value?

A) Triple point B) Boiling pointC) Freezing point D) Critical temperatureE) Absolute zero

A) 5 B) 20 C) 50 D) 100 E) 500

62. In an exothermic reaction, the temperature of a l00gram water bath is raised 5°C. How many calories doesthe water absorb?

A) –173 K B) –100 KC) 100 K D) 200 KE) 446 K

63. What is the Kelvin equivalent of –173° C?

A) 20.4 kJ B) 76.7 kJC) 81.4 kJ D) 408 kJE) 1470 kJ

64. The heat of vaporization of water is 40.7 kJ•mol–1.How much energy is released when 36.0 g of steamcondenses into liquid water at 100ºC?

Base your answer to questions 65 and 66 on thefollowing types of energy.

(A) Lattice energy(B) Potential energy(C) Kinetic energy(D) Electromagnetic energy(E) Vaporization energy

A) A B) B C) C D) D E) E65. Energy that can be used to directly calculate H

A) A B) B C) C D) D E) E66. Energy that binds together ionic solids

67. Base your answer to the following question on thediagram shown below.

A) 1 B) 2 C) 3 D) 4 E) 5Which represents the heat of reaction?

68. CuO + H2 ® Cu + H2O(l) DH= –130.6 kJ

A) –86.6 kJ B) –174.6 kJC) 174.6 kJ D) 126.6 kJE) 42.6 kJ

What is the value of DH if the reaction produced watervapor instead of liquid water? (DH = 44 kJ/mol for thephase change H2O(l) ® H2O(g))

A) B)

C) D)

69. Which of the following graphs represents anexothermic reaction with a low activation energy?

70. H2O(l) ® H2O(s)

A) The volume decreases.B) The heat is released.C) The enthalpy decreases.D) The entropy decreases.E) The process is exothermic.

When water freezes at its normal boiling point of 0oC,which of the following is NOT true?

71. H2O(l) ® H2O(g)

A) DH < 0, DS > 0, DV < 0B) DH < 0, DS < 0, DV < 0C) DH > 0, DS > 0, DV < 0D) DH < 0, DS < 0, DV > 0E) DH > 0, DS > 0, DV > 0

When water boils at its normal boiling point of 100oC,which of the following is true?

72. The heat of combustion for CH6O2N2(g) is –98 kcal.CH6O2N2(g) + O2(g) ® CO2(g) + 2 NO2(g) + 3 H2O(g)

A) –216 kcal B) –182 kcalC) 182 kcal D) +124 kcalE) –124 kcal

What is the heat of formation for CH6O2N2(g)?

73.

A) –67.0 J B) –14.8 J C) –1.30 J D) +1.30 J E) +14.8 J

Based on the table above, what is the DHº for the reaction N2O4 + O2 ® N2O5?

74. C2H6(g) + O2(g) ® 3 H2O(l) + 2 CO2(g)

A) DE + RT B) DE – RTC) DE – RT D) DE + RTE) DE

What is the enthalpy change (DH) for the abovereaction?

A) CH4(g) + Cl2(g) ® CH3Cl(g) + HCl(g)B) 2 NO(g) + O2(g) ® 2 NO2(g)C) C3H8(g) + 5 O2(g) ® 3 CO2(g) + 4 H2O(g)D) 3 O2(g) ® 2 O3(g)E) 3 H2(g) + N2(g) ® 2 NH3(g)

75. In which of the following reactions would there be theleast difference between enthalpy change (DH) and theinternal energy change (DE)?

A) CH4(g) + 3 O2(g) ® CO2(g) + 2 H2O(g)B) 2 FeO(s) + 2 O2(g) ® Fe2O3(s)C) H2(g) + F2(g) ® 2 HF(g)D) CH4(g) + 2 F2(g) ® CF4(g) + 2 H2(g)E) CO2(g) + CaO(s) ® CaCO3(s)

76. In which of the following reactions would there be thegreatest difference between enthalpy change (DH) andthe internal energy change (DE)?

77. C2H4(g) + 3 O2(g) ® 2 H2O(l) + 2 CO2(g)

A) DE + 2RT B) DE – 2RTC) DE D) DE + RTE) DE – RT

What is the DH for the above reaction?

78. 2 C2H2(g) + 3 O2(g) ® 4 CO2(g) + 2 H2O(l);

DHf º C2H2(g) = 54.20 kJ/molDHf º H2O(l) = –68.30 kJ/molDHf º CO2(g) = –94.10 kJ/mol

A) –216.6 kJ B) –621.6 kJC) –310.8 kJ D) 310.8 kJE) –621.6 kJ

What is the standard enthalpy change for this reaction?

A) 1.550 g/cm3 B) 1.55 g/cm3

C) 1.0 g/cm3 D) 1.00 g/cm3

E) 1.000 g/cm3

79. Mass of container: 11.0 gramsMass of solid sample plus container: 31.0 gramsVolume of the solid sample: 20.0 cubic centimeters The density of the solid sample referred to aboveshould be reported as

A) Keeping the solution well mixed by constantstirring

B) Rinsing the beaker that is to hold the solutionto be titrated right before pouring the solutionin

C) Draining the pipet by touching the tip to the sideof the container that is catching

D) Turning the stopcock immediately so that thetitration stops when the indicator changes color

E) Keeping track of the volume of the solution in theburet both at the beginning of the experiment andafter the titration

80. Which of the following is something not to do, or isunnecessary when performing a titration?

A) crystal colors B) solubilitiesC) densities D) boiling pointsE) melting points

81. Two substances, A and B were separated after being insolution by distillation. Distillation works because Aand B have different

82. An experiment is designed to determine the enthalpy(heat) of solution of ammonium chloride, NH4Cl.

A) Measure the temperatures to the nearest 0.01°CB) Determine the mass of the NH4Cl to the nearest

0.001 g.C) Use a sample of NH4Cl with a mass closer to

9.00 g rather than 8.00 g.D) Determine the mass of the solution in the

calorimeter to the nearest 0.01 g.E) Determine the mass of empty calorimiter to the

nearest 0.0001 g.

Which will increase the precision of the heat of solutionof NH4Cl the most?

83. A student is to standardize a 0.5 M solution of KOH by titration. The following materials are available tothe student.Clean, dry 50 mL buret Analytical balance; 250. mL Erlenmeyer flask; Wash bottle filled with distilledwater; Phenolphthalein indicator solution; Potassium hydrogen phthalate, KHP, a pure solid monoproticacid (to be used as the primary standard)(A) Briefly describe (step by step) the technique the student should use to standardize the KOH, using thematerials above.(B) Describe (i.e, set up) the calculations required to determine the concentration of the KOH solution.

A) 5.02 × 10–5 B) 34100C) 0.00003 D) 0.0782 × 10–3E) 32312 × 1052

84. Which number contains exactly 5 significant digits?

A) Titrating the solution with a strong baseB) Paper chromatographyC) Decanting the corn oilD) Evaporating the waterE) Electrolyzing the solution

85. The most effective way of separating a solution of cornoil and water is

A) Evaporating the waterB) Decanting the NaClC) Filtering out the NaClD) Adding solid AgNO3

E) Allowing the solution to settle

86. The most effective way of recovering solid NaCl from awater solution of NaCl is

A) I and II B) II and IIIC) I only D) III onlyE) I, II, and III

87. Which of the following are proper laboratoryprocedures?

I. Wait until hot objects have reached roomtemperature before finding their mass. II. Always rinse a buret with water beforeadding a titrant.III. When mixing solutions, always add water tothe acid.

88. A 0.300 gram sample of a weak, nonvolatile base, X, is dissolved in enough water to make 40.0 mL ofsolution. This is titrated against standardized HCl. Predict how the calculation of the molar mass of Xwould be affected by the following procedures. Explain your answers.(a) After rinsing the buret with distilled water, it is filled with the standard HCl solution. (b) Extra water is added to the 0.300 gram sample of X.(c) The indicator phenolphthalein is used to signal the endpoint.(d) An air bubble passes through the tip of the buret.

89. Describe an experimental set up, along with necessarymeasurements and equations, that can be used todetermine the heat liberated when 1.00 mol of zincreacts with reacts with 2.00 mol of hydrochloric acid.

90. Based on the above table, list the acids in order of increasing acid strength.

A) CH3COOH, NH4+, HIO3

B) HIO3, CH3COOH, NH4+

C) HIO3, HIO3, CH3COOHD) NH4

+, HIO3, CH3COOHE) NH4

+, CH3COOH, HIO3

91. List the following 1.0 M solutions in order ofdecreasing pH.

CaBr2 FeCl3 NaF

A) NaF, CaBr2, FeCl3 B) FeCl3, CaBr2, NaFC) CaBr2, NaF, FeCl3 D) FeCl3, NaF, CaBr2E) CaBr2, FeCl3, NaF

92. What is the correct arrangement of the four 0.01 M solutions in the order of increasing pH?

NH4Cl H2SO4 NA2SO4 HCl

A) NH4Cl, H2SO4, Na2SO4, HClB) HCl, H2SO4, Na2SO4, NH4ClC) Na2SO4, NH4Cl, HCl, H2SO4

D) NH4Cl, Na2SO4, HCl, H2SO4

E) H2SO4, HCl, NH4Cl, Na2SO4

93. HF(aq) + NH3(aq) « NH4+(aq) + F–(aq)

A) The reactants are favored because NH4+ and HF

are acids of equal strength.B) The products are favored because NH4

+ is astronger acid than HF.

C) The reactants are favored because HF is a strongeracid than NH4

+.D) The reactants are favored because NH4

+ is astronger acid than HF.

E) The products are favored because HF is astronger acid than NH4

+.

Which statement is true about the equilibrium reactionabove?

94. HSe– + HTe– « H2Te + Se2– HTe– +Se2– « HSe– +Te2–

A) HSe–, HTe– , H2Te B) HSe–, H2Te, HTe–C) H2Te, HTe–, HSe– D) H2Te, HSe–, HTe–E) HTe–, HSe–, H2Te

If reactants are favored in both the above two reactionsthen what is the order of acids from strongest toweakest?

A) SO32– B) H2O

C) HSO3– D) H2PO4

–

E) NH4+

95. Which can never be a base?

A) receives an electron pair to form a bondB) has resonance structuresC) donates an electron pair to form a bondD) donates an electron to a water moleculeE) receives an electron from a water molecule

96. A molecule or ion is classified as a Lewis base if it

A) CaO B) SO2 C) MgO D) Na2O E) LiO

97. Which of the following ions would hydrolyze toproduce hydronium ions?

98. Consider the following salts:

I. NaF II. NaClO4 III. NaHSO4

A) I and III only B) I and II onlyC) II and III only D) I, II and IIIE) I only

Which of these salts, when dissolved in water, wouldform a basic solution?

A) LiF B) KClO4

C) NaHSO3 D) NH4NO3

E) Li2SO4

99. Which of the following salts dissolves to produce abasic aqueous solution?

A) LiCl B) K3PO4

C) NaClO4 D) NH4NO3

E) HCl

100. Which of the following 0.10 M solutions is basic?

Answer KeyThermochemistry

1. B2. D3. D4. C5. D6. B7. C8. B9. C10. B11. A12. B13. C14. E15. C16. D17. D18. D19. A20. B21. E22. B23. A24. E25. A26. B27. C28. A29. C30. E31. D32. D33. A34. B35. D36. D

37. A38. C39. E40. A41. A42. D43. D44. D45. D46. A47. D48. B49. B50. D51. B52. C53. B54. A55. D56. E57. B58. A59. C60. D61. E62. E63. C64. C65. B66. A67. A68. A69. D70. A71. E72. E

73. D74. A75. A76. B77. A78. B79. D80. B81. D82. C83. (A) 4 essential steps:

1) Weigh KHP2) Rinse buret withsmall amount ofNaOH solution3) Fill buret withNaOH solution4) Add indicator(phenolphthalein)5) Titrate to endpoint(color change)

(B) moles KHP =Mass KHP/ MM KHPmoles KHP = molesOH– at equivalencepoint and (moles OH–

/ liters KOH) = [OH–]84. E85. C86. A87. C88. (essay)

89. In a calorimeter, placea known amount ofzinc into a solution ofexcess HCl. Measurethe temperaturebefore and after thereaction. Use theformula DH = mcalorimetercpDT todetermine the heatreleased. Divide bythe number of molesof zinc to get themolar enthalpychange.

90. E91. A92. C93. E94. E95. E96. C97. B98. E99. A100. B

Answer KeyThermochemistry

88. (a) The calculated molar mass will be too low. The droplets of water remaining in the buret will dilute the HClso that a larger volume is needed. This corresponds to a higher concentration for the basic solution and thus alower molar mass.(b) No change. The amount of the acid used in the titration remains the same.(c) The calculated molar mass would be too high. Less acid would be needed to reach the endpoint.(d) The calculated molar mass would be too low. It would appear as if more acid was used in the titration.

Documents

1.I. Heat is released with an endothermic reaction 4.I. The