5 Steps to a 5 AP Chemistry

28  STEP 2. Determine Your Test Readiness

29. C—The one with the greatest increase in the
    moles of gas.


30. D—Nonspontaneous means ΔG>0. Becoming
    spontaneous at lower temperature means ΔH< 0
    and ΔS<0.

Chapter 10

31. C—Atoms with completely filled shells or sub-
    shells are not paramagnetic. These are: Be, Mg,
    He, Kr, and Zn.


32. C—Transition metal ions are s^0. C could be Cr^3 +.


33. E—Noble gases, except helium, are ns^2 np^6. In
    this case, n =4.


34. D—Halogens are ns^2 np^5. In this case, the halo-
    gen is F.


35. A—The 1p orbital does not exist.


36. D—Definition.


37. E—The electrons enter the 2p orbitals individually.


38. A—Definition.


39. B—The d orbitals are less effectively shielded
    than the s orbitals.


40. C—Mg becomes Mg^2 +. The element is N, which
    can become N^3 −.

Chapter 11

41. C—The iodine has five bonding pairs and one
    lone pair.


42. B—This is the only one with only single bonds.


43. C—Use VSEPR.


44. C—The only ionic bonds are the sodium com-
    pounds. The nitride ion has no internal bonding,
    but the nitrate ion has σand πbonds.


45. C—Numbers of unshared pairs: (A) 1; (B) 0;
    (C) 3; (D) 0; (E) 2


46. C—The carbon on the left is sp^3 , and the other
    is sp^2.

Chapter 12

47. D—Both graphite and diamond are covalent-
    network solids.


48. A—Calcium is a metal, and answer A applies to
    metallic bonding.


49. C—Calcium carbonate is ionic.


50. B—This is a polar molecule.


51. D—Definition.


52. D—This is a consequence of metallic bonding.


53. C—The carbonyl and −OH groups are capable
    of participating in hydrogen bonds.


54. C—The more −OH groups, the more hydrogen
    bonding, and the more soluble in water.


55. B—Definition.

Chapter 13

56. A—Molarity is moles per liter, and the moles are
    already known.

57.D—(0.800 L)(0.50 mol Br−/L) =

0.40 mol needed.

(0.800 L)(0.20 mol Br−/L) =

0.16 mol present.

(0.24 mol Br−to be added)

(1 mol MgBr 2 /2 mol Br−)

58. A—Mole fraction of each =0.5 since the solution
    is equimolar.
    Vapor pressure of CCl 4 =
    0.5 (87 mm Hg) =43.5 mm Hg

Vapor pressure of pentane =

0.5 (450 mm Hg) =225 mm Hg

Mole fraction of CCl 4 in vapor =

43.5 mm Hg/(43.5 +225) mm Hg

59. E—(0.5000 L)(5.00 mol/L)(63.0 g/mol) =158 g


60. B—Since all the molalities are the same, look for
    the one that produces the most ions.