LPC, Chem 1A Final Exam Review, Fall 2002

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A sample of gas collected at 22oC and 600. torr has a volume of 2.55 liters. What volume would the gas occupy (ii) (a) PbO2 (b) SO2 (c) SiO2 (d) TiO2 Lauryl alcohol is obtained from coconut oil and is used to make detergents.

BCC, Fall 2007

    Chem 1A Final Review

    Part A : Multiple-choice questions.

     o1. The boiling point of chlorine gas is 239.2 K at 1 atm. What is this temperature in Fahrenheit (F)?

    oooo (a) 462.6F (b) 29.2F (c) 34.0F (d) 93.2F

    2. A cylindrical metal rod of uniform diameter measures 122.0 cm long and weighs 934.0 grams. If the 3diameter of the rod is 1.90 cm, calculate the density of metal in g/cm. -333333 (a) 2.70 g/cm (b) 1.35 g/cm (c) 2.70 x 10 g/cm (d) 2.70 x 10 g/cm

3. Which of the following involves a chemical change?

     (a) Sugar dissolves in water; (c) Evaporation of rubbing alcohol; o (b) The wood is rotting away; (d) Sulfur melts at 115C. 4+2394. The number of protons, neutrons, and electrons, respectively, in the ionic species Pu is: 94

     (a) 94, 239, 90; (b) 94, 145, 90; (c) 94, 145, 98; (d) 94, 239, 94;

5. A compound with an empirical formula CH may have which of the following molecular formula? 23

     (a) CH (b) CH (b) CH (d) CH 34581218814

6. The formula of ammonium molybdate is (NH)MoO. What is the formula of aluminum molybdate? 424

     (a) AlMoO (b) Al(MoO) (c) Al(MoO) (d) Al(MoO) 444324243

7. Which is the correct formula of ammonium hydrogen phosphate ?

    (a) (NH)HPO (b) (NH)HPO (c) (NH)HPO(d) (NH)HPO 434 424324 334

8. A compound with formula Cr(SO) is named 243

     (a) Dichromium trisulfate (c) Chromium(III) sulfate

    (b) Chromium(II) sulfate (d) Chromium(III) trisulfate

9. Boron reacts with oxygen gas to form a product having which formula?

     (a) BO (b) BO (c) BO (d) BO 233223

10. Name a compound with formula HSO. 23

     (a) Dihydrogen sulfite (c) Sulfurous acid

     (b) Dihydrosulfitic acid (d) Hydrosulfuric acid

11. For the reaction between solid CaCO and aqueous HCl solution, the net ionic equation is: 3

    -2+ (a) Ca + 2Cl ? CaCl; (aq)(aq)2(s)

    -+2 (b) 2H + CO ? HO + CO; (aq)3(aq)2(l)2(g)

    +2+ (c) CaCO + 2H ? Ca + HO + CO; (aq)(aq)3(s)2(l)2(g)

    --2 (d) 2HCl + CO ? HO + CO + 2Cl; (aq)3(aq)2(l)2(g)(aq)

    12. Which solution when reacted with aqueous sodium phosphate, NaPO, will yield a precipitate? 34

     (c) Barium chloride (b) Calcium acetate (a) Silver nitrate (d) All of them


BCC, Fall 2007

    Chem 1A Final Review

    13. Which compound forms a strong electrolyte when dissolved in aqueous solution?

     (a) (NH)PO (b) HPO (c) NHOH (d) CHOH 4343443

    14. A student needs to prepare 2.00 L of 0.100 M NaCO (molar mass = 106 g/mol). The best procedure 23

    is to weigh out:

     (a) 10.6 g of NaCO, add 2.00 L of water and mix well to dissolve the solid. 23

     (b) 21.2 g of NaCO, add 2.00 L of water and mix well to dissolve the solid. 23

     (c) 10.6 g of NaCO and add enough water to make 2.00 L of homogeneous solution. 23

     (d) 21.2 g of NaCO and add enough water to make 2.00 L of homogeneous solution. 23

15. For the reaction between strong nitric acid and potassium hydroxide (a strong base), the correct net

    ionic equation is:

     -+ (a) H + OH ? HO; (aq)(aq)2(l)

    -- (b) HNO + OH ? HO + NO; 3(aq)(aq)2(l)3(aq)

    ++ (c) H + NaOH ? HO + Na; (aq)(aq)(aq)2(l)

    -+ (d) HNO + NaOH ? HO + Na + NO(aq)3(aq)(aq)2(l)3(aq)

16. For an acid-base reaction between acetic acid (a weak acid) and sodium hydroxide (a strong base), the

    correct net ionic equation is:

     -+ (a) H + OH ? HO; (aq)(aq)2(l)

    -- (b) HCHO + OH ? HO + CHO; 232(aq)(aq)2(l)232(aq)

    ++ (c) H + NaOH ? HO + Na; (aq)(aq)(aq)2(l)

    -+ (d) HCHO + NaOH ? HO + Na + CHO(aq)232(aq)(aq)2(l)232(aq)

17. How many grams of KOH are present in 400. mL of 0.250 M KOH solution?

     (a) 5.61 g (b) 14.0 g (c) 0.100 g (d) 100. g

18. A chemist needs 2.5 L of 0.24 M HCl. What volume of 12 M HCl must be diluted to make this


     (a) 1.2 L (b) 0.60 L (c) 50. mL (d) 5.0 mL

     o19. A sample of gas collected at 22C and 600. torr has a volume of 2.55 liters. What volume would the

    gas occupy at STP?

    (a) 1.86 L (b) 2.18 L (c) 2.99 L (d) 3.49 L

     o20. A 25-liter gas tank contains 0.50 mole of H gas and 0.50 mole of N gas at 20C. Which of the 22

    following statements is true?

     (a) N gas exerts a greater pressure due to its heavier molecules; 2

     (b) N gas has the greater average kinetic energy; 2

     (c) H gas has the greater root-mean-square speed; 2

     (d) H gas exerts a greater pressure because of its higher frequency of collisions. 2

21. Which of these gases has the greatest rate of effusion under the same conditions?

     (a) NO (b) HCl (c) NH (d) HS 32


BCC, Fall 2007

    Chem 1A Final Review

22. Nitrogen and hydrogen gases react to form ammonia gas as follows:

     N + 3H ? 2NH; 2(g)2(g)3(g)

     At a certain temperature and pressure, 7.0 L of N is reacted with 21.0 L of H. If all N and H are 2222

    consumed, what volume of NH will be produced at the same temperature and pressure? 3

     (a) 7.0 L (b) 14 L (c) 21 L (d) 28 L

23. What is the algebraic sign (positive “+” or negative “–“) for q and w in the following process at 1 atm oand 100C?

     HO ? HO 2(l)2(g)

     (a) q is positive, w is negative (b) q is negative, w is positive

     (c) both of them are positive (d) both of them are negative

     o24. A sample of ideal gas at 25C expands from 1.00 liters to 10.00 liters against a constant pressure of

    1.00 atm. How much work (in Joules) is performed on the surroundings? (1 L.atm = 101.3 J)

     (a) 912 J (b) 1013 J (c) 2530 J (d) 253 J

     o25. When 100.0 grams of water at 20.0C is mixed with 25.0 grams of water at a certain temperature, the ofinal temperature of the resulting mixture is 32.0C. What was the initial temperature of the second owater sample? (specific heat of water = 4.184 J/g.C) oooo (a) 80.0C (b) 68.0C (c) 48.0C (d) 41.6C

     o26. A 40.2 g sample of a metal is heated to 99.3C and then placed in a calorimeter containing 120.0 g of ooowater (s = 4.18 J/g.C) at 21.8C. The final temperature of water and metal is 24.5C. Identify the

    metal used?

     oo (a) Aluminum (s = 0.89 J/g.C) (b) Copper (s = 0.38 J/g.C) oo(c) Iron (s = 0.45 J/g.C) (d) Lead (s = 0.14 J/g.C)

     8o27. The total volume of hydrogen gas to fill the Hindenburg was 2.00 x 10 L at 1.00 atm and 25.0C.

    How much energy was evolved when it burned?

     H(g) + ? O(g) ? HO(l); ?H = -286 kJ 222

    46910 (a) 2.86 x 10 kJ (b) 8.18 x 10 kJ (c) 2.34 x 10 kJ (d) 5.72 x 10 kJ

28. The heat of formation of FeO(s) is 826 kJ/mol. Calculate the enthalpy change for the reaction: 23

     4Fe(s) + 3 O(g) ? 2FeO(s) when 55.8 g of iron is reacted. 223

     (a) -206 kJ (b) -413 kJ (c) -826 kJ (d) -1650 kJ

29. Which of the following is an exothermic process?

    ------+2 (a) O ? O + e; (b) O ? O + e; (c) O ? O + e; (d) none of them;

30. Which of the following processes requires the most amount of energy?

    ----+2+2+3++2++2+ (a) Al ? Al + e; (b) Al ? Al + e; (c) Mg ? Mg + e; (d) Na ? Na + e;


BCC, Fall 2007

    Chem 1A Final Review

    31. As the strength of the attractive intermolecular forces increases, which one of the following will also


     (a) The enthalpy of vaporization

    (b) The normal boiling temperature

     (c) The extent of deviations from the ideal gas behavior

     (d) The vapor pressure of a liquid

32. Hydrogen bonds account for which of the following observation?

     (a) Hydrogen forms stable diatomic molecules

     (b) Hydrogen gas has a very low boiling point

     (c) Water is a liquid at room temperature

     (d) Water is denser than ice

33. Which of the following molecules is not expected to exhibit hydrogen bondings in the liquid state?

     (a) CHF (b) CHNH (b) CHOH (d) None of them 3323

34. For each of the following sets, which substance would you expect to have the highest boiling point?

     (i) (a) CH (b) CF (c) SiH (d) SiF 4444

     (ii) (a) NH (b) PH (c) AsH (d) SbH 3333

     (iii) (a) CH (b) NH (c) CH (d) NH 242443

35. For each of the following sets, which substance is expected to have the highest melting point?

     (i) (a) CO (b) KO (c) NO (d) SO 2222

     (ii) (a) PbO (b) SO (c) SiO (d) TiO 2222

     (iii) (a) Br (b) I (c) P (d) S 2248

36. On a relative basis, the weaker the intermolecular forces in a substance,

     (a) the higher the surface tension of the liquid

     (b) the higher the vapor pressure of the liquid

     (c) the higher the viscosity

     (d) None of the above.

37. CO molecules in dry ice are attracted to one another by what forces 2

     (a) London dispersion forces only

     (b) London dispersion forces and permanent dipole-dipole attractions

     (c) Permanent dipole-dipole attractions only

     (d) Permanent dipole-dipole attractions and ionic bonds.

     o 38. If the vapor pressure of water at 100C is 760.0 torr and its enthalpy of vaporization is 40.7 kJ/mol, ocalculate its vapor pressure at 37C. (R = 8.314 J/mol.K)

     (a) 699 torr (b) 281 torr (c) 25.4 torr (d) 52.8 torr

     339. The molar volume of a certain form of solid lead is 18 cm/mol. Assuming lead forms cubic closest

    packed lattice structure, determine the following:


BCC, Fall 2007

    Chem 1A Final Review

     (i) The number of lead atoms per unit cell

     (a) 4 (b) 6 (c) 8 (d) 12

     (ii) The volume of a single cell

    6383103123 (a) 1.20 x 10 pm (b) 1.20 x 10 pm (c) 1.20 x 10 pm (d) 1.20 x 10 pm

     (iii) The radius of a Pb atom.

     (a) 1.74 pm (b) 17.4 pm (c) 174 pm (d) 1740 pm

40. Which of the following statements about solid copper, which forms face-centered cubic unit cell, is


     (a) There are four Cu atoms per unit cell

     (b) The solid has a cubic closest-pack structure

     (c) The number of atoms surrounding each Cu atom is 12

     (d) The length of a body diagonal is four times the radius of Cu atom.

41. Chromium metal crystallizes as a body-centered cubic lattice. The relationship between the radius of

    a chromium atom ? and the length of an edge of the unit cell (S) is:

     (a) r = (S?3)/4 (b) r = (S?2)/4 (c) r = S/2 (d) r = (3?S)/4

    42. Chromium metal crystallizes as a body-centered cubic lattice. If the atomic radius of Cr is 125 pm, 3what is density of chromium metal in g/cm? 3333 (a) 5.52 g/cm (b) 7.18 g/cm (c) 7.81 g/cm (d) 8.92 g/cm

     2+43. Calcium fluoride (CaF) crystallizes in a structure in which the Ca ions occupy the face-centered 2-lattice points and F ions fill up the tetrahedral holes. What is the number of fluoride ions in the unit


     (a) 2 (b) 4 (c) 6 (d) 8

     -244. A certain metal oxide crystallizes in such a way that the O ions form the face-centered cubic n+structure and the metal M ions occupy the tetrahedral holes. Which is the most probable formula of

    the metal oxide?

     (a) MO (b) MO (c) MO (d) MO 223

45. Silver chloride crystallizes with the sodium chloride (rock salt) structure. If the length of the unit cell

    edge is 555 pm, what is the density of AgCl?

     33363 (a) 1.39 g/cm (b) 2.78 g/cm (c) 5.57 g/cm (d) 1.39 x 10 g/cm

     o46. At 1.00 atm and 0C, which phase(s) of HO can exist? 2

     (a) Ice only (b) Ice and water (c) Ice and water vapor (d) water and water vapor

47. Which of the following is a covalent network solid?

     (a) BaO (b) PbO (c) SiO (d) TiO 2222

48. Which pair compounds consists of an ionic solid and a molecular solid, respectively?

     (a) AlO and BO (b) BaCl and CoCl (c) CO and SO (d) BO and CrO 232322222323


BCC, Fall 2007

    Chem 1A Final Review

    49. The substance with the highest melting temperature in the following list is:

     (a) HO (b) CO (c) MgF (d) SiF 2224

50. Which compound has the greatest lattice energy ?

     (a) LiF (b) NaF (c) MgF (d) CaF 22

51. When a nonpolar liquid displays a convex meniscus, which of the following explains this behavior?

     (a) It has a low surface tension, and therefore clings to the glass.

     (b) The cohesive forces are stronger that the adhesive forces toward the glass.

     (c) The adhesive forces toward the glass are stronger than the cohesive forces.

     (d) The liquid has a low viscosity.

52. You are given the following boiling point data:

    oo (a) Water, HO: 100C; (b) Methanol, CHOH: 65.0C; 23oo (c) ethanol, CHCHOH: 78.5C; (d) diethyl ether, CHCH-O-CHCH: 34.5C. 323223

     Which one of the above liquids would you expect to have the highest vapor pressure at room


     oo53. How much energy is needed to convert 64.0 g of ice at 0.00C to water at 75C? oo (specific heat of ice = 2.10 J/g.C; specific heat of water = 4.18 J/g.C; heat of fusion = 333 J/g, and

    heat of vaporization = 2260 J/g)

     (a) 10.1 kJ (b) 20.7 kJ (c) 31.4 kJ (d) 41.4 kJ

     o54. When 5.00 g of benzene (CH) is completely vaporized at a constant pressure of 1.00C and at its 66

    normal boiling point of 353.0 K, 1.97 kJ of heat is absorbed and the volume change is +1.85 L.

    Calculate the molar enthalpy of vaporization (?H) for benzene. vap

     (a) 9.85 kJ/mol (b) 30.8 kJ/mol (c) 36.6 kJ/mol (d) 44.0 kJ/mol

     o55. The triple point of iodine is at 90 torr and 115C. This means that liquid I 2

    o (a) is more dense than solid I; (b) cannot exist above 115C; 2

     (c) cannot exist at 1 atm pressure; (d) cannot have a vapor pressure less than 90 torr.

     oo56. The triple point of CO is at 5.2 atm and 57C. Under conditions of 1.00 atm pressure and 20C, 2

    solid CO will: 2

     (a) remain solid (b) boil (c) melt (d) sublime.

57. When NaOH dissolves in water, the resulting solution becomes warm. Which of the following

    equation represents the correct dissolution process for NaOH?

     --+++2(a) NaOH ??Na + OH + heat; (c) NaOH + heat ? ?Na + O + H; (aq)(aq)(s) (aq)(s) (aq)(aq)

    --++(b) NaOH + heat ? ?Na + OH ; (d) Na + OH ? NaOH + heat. (aq)(aq)(s) (aq)(aq)(aq)

     -+58. Sodium chloride is soluble in water because of the strong interactions between Na and Cl ions with

    HO molecules. These interactions are called _______________ attractions. 2

     (a) dipole-dipole (c) ion-dipole

     (b) dipole-induced dipole (d) London dispersion


BCC, Fall 2007

    Chem 1A Final Review

    59. Which of these substances is expected to be most soluble in hexane, CH (a nonpolar solvent)? 614

     (a) NaF (b) SiF (c) AlF (d) SF432

60. Which of the following solutions, at the same concentration, will have the highest boiling point?

     (a) Al(NO) (b) Ca(NO) (c) NaNO (d) CHNO 3332332

61. Compared to pure water, an aqueous solution of sodium chloride will exhibit:

    (a) lower vapor pressure, lower freezing point and lower boiling point;

    (b) higher vapor pressure, higher freezing point and higher boiling point;

    (c) lower vapor pressure and lower freezing point, but a higher boiling point;

    (d) higher freezing point, but lower vapor pressure and lower boiling point

    62. What is the molality of a solution of 50.0 g propanol (CHCHCHOH) in 152 mL of water, if the 322

    density of water is 1.00 g/mL?

     (a) 5.47 m (b) 0.00547 m (c) 0.329 m (d) 0.833 m

63. An aqueous solution is 9.0% glucose (CHO) by mass. What is the molality of the solution? 6126

     (a) 0.50 m (b) 0.55 m (c) 0.055 m (d) 0.090 m

64. A 26.35% solution of Mg(NO) has a density of 1.108 g/mL. What is the molarity of the solution? 32

     (a) 0.1776 M (b) 1.968 M (c) 7.470 M (d) 2.412 M

65. A 26.35% solution of Mg(NO) has a density of 1.108 g/mL. What is the molality of the solution? 32

     (a) 2.412 m (b) 1.776 m (c) 0.3578 m (d) 3.578 m

66. A 20.0-g sample of methyl alcohol (CHOH, molar mass = 32.0 g/mol) was dissolved in 30.0 g of 3

    water. The mole fraction of CHOH is: 3

     (a) 0.273 (b) 0.400 (c) 0.625 (d) 0.728

67. Rank the following compounds according to their increasing solubility in water.


     (a) I < III < IV < IV < II (b) I < II < IV < III

    (c) III < IV < II < I (d) I < II < III < IV

68. When 0.800 g of NHNO was added to 150.0 g of water in a styrofoam cup, the temperature dropped 43ooby 0.413C. The heat capacity of HO is 4.18 J/g.C. Assuming that the specific heat of the solution 2

    equals that of pure water and that the calorimeter neither absorbs nor leaks heat. Calculate the molar

    heat of solution for solid NHNO. 43

     (a) 2.60 kJ/mol (b) +2.60 kJ/mol (c) +26.0 kJ/mol (d) +260. kJ/mol

69. Which of the following mixtures is most likely to form an ideal solution?

     (a) water and isopropanol (CHCH(OH)CH) (b) methanol (CHOH) and ethanol (CHCHOH) 33332

     (c) benzene (CH) and octane (CH) (d) ethanol (CHCHOH) and benzene (CH) 668183266


BCC, Fall 2007

    Chem 1A Final Review o70. At 40C, heptane has a vapor pressure of 92.0 torr and octane has a vapor pressure of 31.2 torr.

    Assuming ideal behavior, what is the vapor pressure of a solution that contains twice as many moles

    of heptane as octane?

     (a) 51.5 torr (b) 61.6 torr (c) 71.7 torr (d) 76.8 torr

71. Thyroxine, and important hormone that controls the rate of metabolism in the body, can be isolated

    from the thyroid gland. If 0.455 g of thyroxine is dissolved in 10.0 g of benzene, the freezing point of oothe solution is 5.144C. The freezing point of pure benzene is 5.444C and the freezing point odepression constant (K) is 5.12C/m. What is the molar mass of thyroxine? f

     (a) 2330 g/mol (b) 777 g/mol (c) 376 g/mol (d) 285 g/mol

72. A 1% sugar solution and a 10% sugar solution are separated by a semi-permeable membrane. There

    will be a net flow of which of the following across the membrane?

    (a) sugar molecules from the 10% solution to the 1% solution;

    (b) water molecules from the 10% solution to the 1% solution;

    (c) sugar molecules from the 1% solution to the 10% solution;

    (d) water molecules from the 1% solution to the 10% solution

    73. A 2.50-g sample of a hydrocarbon solute (molar mass = 340 g/mole) is dissolved in benzene to make oa 350-mL solution. What is the osmotic pressure of the solution at 20.0C?

     (a) 110. torr (b) 220. torr (c) 380. torr (d) 440. torr

     o74. What is the osmotic pressure of 0.10 M NaCl solution at 25C ?

     (a) 2.4 atm (b) 4.9 atm (c) 0.41 atm (d) 0.82 atm

    75. A 1.40-g sample of synthetic organic polymer was dissolved in enough benzene to make 100. mL osolution, which exhibits an osmotic pressure of 18.6 torr at 25C. What is the molar mass of the

    polymer? 3457 (a) 5.72 x 10 g/mol (b) 1.40 x 10 g/mol (c) 3.39 x 10 g/mol (d) 1.06 x 10 g/mol


Part B:

B1. Give the systematic name for each of the following compounds:

     (a) KHPO:______________________________ (f) NO:_____________________________ 242

     (b) (NH)CO:____________________________ (g) HClO: ___________________________ 4234

     (c) Pb(NO) :_____________________________ (h) Sn(CHO):_______________________ 322322

     (d) CoCl.6HO:___________________________ (i) BO :_____________________________ 2223

     (e) Al(SO): _____________________________ (j) HPO:____________________________ 24334


BCC, Fall 2007

    Chem 1A Final Review

    B2. Write the correct formula for each of the following compounds:

     (a) Ammonium dichromate:_______________ (f) Acetic acid:___________

     (b) Sodium hypochlorite:______________ (g) Calcium phosphate:___________

     (c) Copper(II) sulfate pentahydrate: __________ (h) Dinitrogen pentoxide:_________

     (d) Mercury(I) nitrate: ________________ (i) Hydrosulfuric acid:__________

     (e) Lead(II) chromate: ______________ (j) Silicon tetrafluoride:____________

B3. Complete and balance the following equation and write its net ionic equation:

     (a) ___BaCl + ___NaSO ? __________ + ____________; 2(aq)24(aq)

     (b) ___AgNO + ___NaPO ? _________ + ____________ 3(aq)34(aq)

     (c) ___Pb(NO) + ___KI ? _________ + __________ 32(aq)(aq)

B4. Balance the following redox reaction in acidic solution using the half-equation method:

    +3+ ___CrO + ___HO + ___H ? ___Cr + ___HO + ___O (aq)(aq)27(aq)22(aq)2(l)2(g)

B5. Balance the following redox reaction in basic solution using the half-equation method:

     --- ___I + ___OH ? ___IO + ___I + ___HO(aq)(aq)2(aq)(aq)32(l)

B6. Magnesium metal and magnesium oxide react with hydrochloric acid according to the following


     Mg + 2HCl ? MgCl + H (s)(aq)2(aq)2(g)

     MgO + 2HCl ? MgCl + HO (s)(aq)2(aq)2(l)

     A student obtained a 0.100 g of magnesium strip without polishing it and then reacted it with dilute

    hydrochloric acid in a gas buret (eudiometer). The hydrogen gas produced is collected above water at o22 C. (a) If 85.0 mL of H gas was collected and the total gas pressure was 728 torr, how many 2

    moles of H were collected? (b) How many grams of pure magnesium reacted with the acid solution? 2

    (c) What is the percentage (by mass) of magnesium oxide on the strip? (The vapor pressure of water oat 22C is 21 torr; R = 0.08206 L.atm/(mol.K))

    (Answer: (a) 0.00336 mol H; (b) 0.0818 g Mg; (c) 18.2% MgO) 2


BCC, Fall 2007

    Chem 1A Final Review

    B7. (a) Calculate the enthalpy change (?H) for the following reaction: rxn

     CHCHOH + 3 O ? 2CO + 3HO; 32(l)2(g)2(g)2(g)

    o [?H (kJ/mol): CHCHOH = -278; CO = -393.5; HO = -242] f32(l)2(g)2(g)

     (b) How many grams of ethyl alcohol (CHCHOH) must be burned to provide enough energy to heat 32ooo350.0 g of water from 22.0 C to 100.0C? (specific heat of water = 4.184 J/g.C)

    (Answer: (a) -1235 kJ; (b) 4.26 g)

     ooB8. If 225 grams of ice at 0C absorbs 100.0 kJ of heat, what would be the final state: ice and water at 0C oor water only? If the final state is water, determine its final temperature. (Answer: water at 26.4C) o(Specific heat of water = 4.184 J/g.C; heat of fusion, ?H = 6.02 kJ/mol) fus

B9. Tungsten crystallizes in a body-centered cubic arrangement and the measurement of each side of the

    unit cell is 321 pm long. Calculate the atomic radius and the density of tungsten. (Atomic mass of -24-10tungsten = 183.85 u; 1 u = 1.66 x 10 g; 1 pm = 10 cm) 3 (Answer: atomic radius = 139 pm; density = 18.4 g/cm)

B10. For each of the following substances, predict whether it is more soluble in water or in hexane (CH), 614

    which is a nonpolar solvent)

     (a) CHCl (e) HF 22

     (b) CHOH (f) S 38

     (c) NaOH (h) HSO 23

     (d) CClF (i) CH 22818

     oB11. (a) If the solubility of KNO is 28 g per 100 g of water at 20C, what is its solubility in 125 g of water 3

    at the same temperature? (b) What is the percentage (by mass) of KNO in a saturated solution of 3oKNO at 20C? (c) What is the molality of a saturated solution of KNO ? 33

     (Answer: (a) 35 g; (b) 22% (by mass); (c) 2.8 m)

    B12. If concentrated nitric acid solution is 70.0% (by mass) in HNO and the density of the solution is 1.48 3

    g/mL, calculate the molarity and molality of the acid. (Answer: 16.4 M; 37.0 m)


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