Solutions for Practice Problems for Chem 11 Final

Solutions to odd numbered homework problems from McQuarrie 4th edition

Chapter 1

5. (a) 2.77 x 10-8

(b) 1.82 x 10-3

(c) 1.23 x 108

(d) 1.254 x 103

7. 120.6 x 10-25

9. (a) centi (b) micro (c) milli (d) giga (e) mega (f) atto

11. (d) < (a) < (e) < (c) < (b) = (f)

13. 4.189 x 10-30 m3

15. 13.6 g/cm3

17. -268.93 oC

-426.47 oF

19. 150 m

25. -0.6 %

29. (a) 3 (b) 4 (c) 4 (d) 2 (e) unlimited

31. (a) 2 (b) 2.08 x 104 (c) 2.8 (d) 2.4 x 10-4

35. (a) 0.215 m (b) 7.56 m (c) 120 pg (d) 15 Gbyte

(e) 6.67 x 10-3 cm3

51. (a) and (b) 59. (a) Group 1 average = 11.4 g/cm3

Group 2 average = 11.4 g/cm3

Group 3 average = 11.1 g/cm3

(b) Group 1 and 2 data is the most accurate since the % error is the lowest.

(c) Group 2 is the most precise since the three measurements are closest to each other.

61. 4.57 mL

73. No

Chapter 2

19 (a) lithium sulfide

(b) barium oxide

(c) magnesium phosphide

(d) cesium bromide

21. (a) silicon carbide

(b) gallium phosphide

(c) aluminum oxide

(d) beryllium chloride

23. (a) chlorine trifluoride and chlorine pentafluoride

(b) sulfur tetrafluoride and sulfur hexafluoride

(c) krypton difluoride and krypton tetrafluoride

(d) bromine oxide and bromine dioxide 25. (a) nitrogen dioxode

(b) ammonia

(c) zinc sulfide

(d) potassium oxide

77. (a) 53 protons in I and 53 protons in I-

(b) 78 neutrons in I and 78 neutrons in I-

(c) 53 electrons in I and 54 electrons in I-

79. In the first compound we have 1.87/1.87 = 1.00. In other words there is 1.00 g of oxygen for every 1.00 g of sulfur.

In the second compound we have 5.91/3.94 = 1.50. In other words there is 1.50 g of oxygen for every 1.00 g of sulfur.

The ratio 1.50/1.00 = 3/2 is itself a small whole number ratio thus illustrating the law of multiple proportions.

81. Atomic mass = 31.1, the element is phosphorous

Chapter 10

1. (a) calcium cyanide (b) silver perchlorate (c) potassium permanganate (d) strontium chromate

3. (a) ammonium sulfate (b) ammonium phosphate (c) calcium phosphate (d) potassium phosphate

5. (a) mercury (I) chloride (b) chromium (III) nitrate (c) cobalt (II) bromide (d) copper (II) carbonate

7. (a) Na2S2O3 (b) KHCO3 (c) NaClO (d) CaSO3

9. (a) Na2SO3 (b) K3PO4 (c) Ag2SO4 (d) NH4NO3

11. (a) Cr2O3 (b) Sn(OH)2 (c) Cu(C2H3O2)2 (d) Co2(SO4)3

13. (a) H2S (b) Al2O3 (c) K2Cr2O3 (d) Ni(C2H3O2)2 19. (a) organic (b) binary (c) organic (d) oyyacid

21. (a) sulfurous (b) bromic (c) hypophosphorous (d) periodic

23. (a) potassium hypobromite (b) calcium hydrogen phosphite

(c) lead (II) chlorite (d) nickel (II) perchlorate

Chapter 3

7. (a) 2 Na (s) + I2 (s) → 2 NaI (s)

(b) Sr (s) + H2 (g) → SrH2 (s)

(c) Ba (s) + Cl2 (g) → BaCl2 (s)

(d) Mg (s) + O2 (g) → MgO2 (s)

Chapter 11

1. (a) 0.519 mol (b) 4.1 mol (c) 638 mol (d) .0922 mol

21. empirical formula is C3H5O molecular formula is C3H5O

23. empirical formula is NaPO3 molecular formula is Na6P6O18

25. empirical formula is C3H4O3

81. 110 g of Sn required

83. empirical formula is C5H4 molecular formula is C10H8 Chapter 10

17. HCl, HClO, HC2H3O2

33. (a) decomposition (b) combination (c) single displacement (d) double displacement

51. (a) CuCl2 (aq) + Na2S (aq) → CuS (s) + 2 NaCl (aq)

Cu2+ (aq) + S2- (aq) → CuS (s)

(b) MgBr2 (aq) + K2CO3 (aq) → MgCO3 (s) + 2 KBr (aq)

2+ 2- Mg (aq) + CO3 (aq) → MgCO3 (s)

(c) BaCl2 (aq) + K2SO4 (aq) → BaSO4 (s) + 2 KCl (aq)

2+ 2- Ba (aq) + SO4 (aq) → BaSO4 (s)

(d) Hg2(NO3)2 (aq) + 2 KCl (aq) → Hg2Cl2 (s) + 2 KNO3 (aq)

2+ - Hg2 (aq) + 2 Cl (aq) → Hg2Cl2 (s)

53. (a) H2SO4 (aq) + 2 NaHCO3 (aq) → 2 CO2 (g) + 2 H2O (l) + Na2SO4 (aq)

+ - 2 H (aq) + 2 HCO3 (aq) → 2 CO2 (g) + 2 H2O (l)

(b) 2 HNO3 (aq) + CaS (aq) → H2S (g) + Ca(NO3)2 (aq)

+ 2- 2 H (aq) + S (aq) → H2S (g)

(c) 2 HCl (aq) + Na2SO3 (aq) → SO2 (g) + H2O (l) + 2 NaCl

+ 2- 2 H (aq) + SO3 (aq) → SO2 (g) + H2O (l)

55. (a) 2 HClO3 (aq) + Ba(OH)2 (aq) → 2 H2O (l) + Ba(ClO3)2 (aq)

+ - H (aq) + OH (aq) → H2O (l) (b) HC2H3O2 (aq) + KOH (aq) → H2O (l) + KC2H3O2 (aq)

- - HC2H3O2 (aq) + OH (aq) → H2O (l) + C2H3O2 (aq)

(c) 2 HI (aq) + Mg(OH)2 (s) → 2 H2O (l) + MgI2 (aq)

+ 2+ 2 H (aq) + Mg(OH)2 (s) → 2 H2O (l) + Mg (aq)

(d) H2SO4 (aq) + 2 RbOH (aq) → 2 H2O (l) + Rb2SO4 (aq)

+ - H (aq) + OH (aq) → H2O (l)

61. (a) calcium oxidized, chlorine reduced (b) aluminum oxidized, oxygen reduced (c) rubidium oxidized and bromine reduced (d) sodium oxidized and sulfur reduced

63. (a) 2 (b) 6 (c) 1 (d) 2

73. Place the metal in a solution of HCl. If the metal dissolves and hydrogen gas is produced, the metal is nickel since nickel is more active than hydrogen. If no reaction occurs then the metal is silver since silver is less active than hydrogen. Chapter 12

3. 0.0250 M

7. 8.3 mL

13. HI is a strong electrolyte, NH4Br is a strong electrolyte, HC2H3O2 is a weak electrolyte, KOH is a strong electrolyte, CH3OH is a nonelectrolyte

15. 0.30 M in Ca2+ and 0.60 M in OH-

2+ 2- 27. 3.93 g of Cu(s) produced, [Zn ] = 0.165 M, [SO4 ] = 0.165 M

29. 0.171 M

31. (a) 2.8 uL

(b) 8.33 mL

37. 92.0 g/mol

3+ - 43. [Sc ] = .0495 M, [NO3 ] = 0.149 M

45. 0.0500 M

53. 0.200 M

63. 10.1 mL, 2.51 g

81. 71.3%

Chapter 13

41. 0.901 g

43. 0.54 g

49. 442 m/s

53. 200 mL/hr.

55. 70.5 g/mol 63. 16.7 bar

73. 480 g

75. C3H6O3

77. 595 OC

81. 0.733 g

85. 91.8 g/mol

87. 87.0% Zn, 13.0% Al

Chapter 14

61. -46.3 kJ/g , -2040 kJ/mol

63. 370 g

65. -827 kJ/mol

73. (a) work done by the system on the surroundings, w is (-)

(b) no work is done

(c) work done on the system by the surroundings, w is (+)

(d) work done by the system on the surroundings, w is (-)

83. (a) U = -564.2 kJ/mol

(b) U = -506.3 kJ/mol

(c) U = -184.6 kJ/mol

87. -1.48 x 103 kJ Chapter 4

3. 4.41 aJ (4.41x10-18 J)

5. 0.52 MJ

17. 3.33 m

19. 285 nm

21. 6 photons

31. 3.97 x 10-12 m = 3.97 pm

37. Wavelegth will be greater.

45. 0.5450 aJ (5.450x10-19 J)

69. 4→3 , 1855 nm 4→2 , 484.7 nm 4→1 , 97.15 nm 3→2 , 656.1 nm 3→1 , 102.5 nm 2→1 , 121.5 nm

Chapter 5

5. (b) 1p (d) 2d

9. If l=2 then n must be greater than or equal to 3. If ml = 3 then l must be greater than or equal to 3. 11. n l ml ms

5 2 2 +1/2

5 2 2 -1/2

5 2 1 +1/2

5 2 1 -1/2

5 2 0 +1/2

5 2 0 -1/2

5 2 -1 +1/2

5 2 -1 -1/2

5 2 -2 +1/2

5 2 -2 -1/2

13. s orbital 2 p subshell 6 d subshell 10 f subshell 14

27. (a) [Ar]4s2

(b) [Ar]4s23d104p5

(c) [He]2s22p1

(d) [Ar]4s23d10

(e) [Xe]6s24f145d4

31. (a) 2

(d) 4 37. (a) 0

39. (a) Ar (b) N (c) Ne

(d) I (e) Ar