MULTIPLE CHOICE.  Choose the one alternative that best completes the statement or answers the question.
The picture shown below represents a two-dimensional lattice of atoms M and X.  

1)  What is the formula of the compound formed from M and X? 1)   _______ 
A) MX B)  MX2 C)  MX3 D)  MX4 

2)  The wavelength of light used to observe an object must be ________ than the object itself. 2)   _______ 
A) of lower energy B)  smaller 
C) larger D)  of higher energy 

3)  Which of the intermolecular forces is the most important contributor to the high surface tension shown by water? 3)   _______ 
A) dispersion forces B)  hydrogen bonding 
C) ion-dipole forces D)  dipole-dipole forces 

4)  Pencil lead is actually 4)   _______ 
A) fullerene. B)  silica. C)  graphite. D)  lead. 

The phase diagram of a substance is shown below. 

5)  What is the physical phase of the substance at T = 100 K and P = 0.1 atm? 5)   _______ 
A) gas B)  solid 
C) liquid D)  supercritical fluid 

6)  If figure (1) represents the vapor pressure of water at 25eC, which figure represents the vapor pressure of ethanol, CH3CH2OH at 25eC? 6)   _______ 
A) figure (2) B)  figure (3) C)  figure (4) 

7)  In the drawing of acetaldehyde, CH3CHO, the largest partial positive charge (d+) occurs on 7)   _______ 
A) atom (a). B)  atom (b). C)  atom (c). D)  atom (d). 

8)  In the drawing of acetaldehyde, CH3CHO, the largest partial negative charge (d -) occurs on 8)   _______ 
A) atom (a). B)  atom (b). C)  atom (c). D)  atom (d). 

9)  Which transition could occur if a solid is heated at a pressure above the triple point pressure? 9)   _______ 
A) condensation B)  deposition 
C) sublimation D)  melting 

10)  Which transition could occur if a solid is heated at a pressure below the triple point pressure? 10)   ______ 
A) melting B)  sublimation 
C) condensation D)  deposition 

11)  Which has the smallest dipole-dipole forces? 11)   ______ 
A) HCl B)  CH3F C)  N2 D)  CO 

12)  The critical temperature of a substance is the 12)   ______ 
A) temperature at which all three phases can exist in equilibrium. 
B) temperature above which the compound decomposes. 
C) highest temperature at which the liquid phase can exist in equilibrium with the gas phase. 
D) temperature at which sublimation occurs. 

13)  Cubic closest-packing 13)   ______ 
A) has a simple cubic unit cell. 
B) has a face-centered cubic unit cell. 
C) has a body-centered cubic unit cell. 
D) has the same unit cell as hexagonal closest-packing. 

14)  Cesium has a radius of 272 pm and crystallizes in a face-centered cubic unit cell. What is the edge length of the unit cell? 14)   ______ 
A) 628 pm B)  544 pm C)  385 pm D)  314 pm 

Use the diagram below to answer the following questions.

15)  Melting occurs along the 15)   ______ 
A) CD line. B)  AC line. 
C) CB line. D)  all of the above 

16)  Hydroquinone is an antioxidant that is also used as a photographic reducer and developer. The normal boiling point of hydroquinone is 310eC. Calculate the pressure at which hydroquinone will boil at 200eC given that its  is 73.38 kJ/mol. 16)   ______ 
A) 1.35 mm Hg B)  1.210 x 10-4 mm Hg 
C) 22.5 mm Hg D)  757 mm Hg 

17)  The vapor pressure of a pure liquid increases as the 17)   ______ 
A) temperature of the liquid phase decreases. 
B) temperature of the liquid phase increases. 
C) average kinetic energy of the molecules in the liquid phase decreases. 
D) intermolecular attractive forces increase. 

18)  How many unit cells share an atom that is on the face of a cubic unit cell? 18)   ______ 
A) 8 B)  2 C)  4 D)  1 

A certain mineral, MxM'yAz, crystallizes in the cubic unit cell shown below. M and M' represent cations and A represents the anions.

19)  What is the empirical formula of the mineral? 19)   ______ 
A) MM'A3 B)  M2M'A3 C)  MM'A D)  M8M'A6 

20)   has a radius of  pm and crystallizes in a body-centered cubic structure. What is the edge length of the unit cell? 20)   ______ 
A)  pm B)   pm C)   pm D)   pm 

21)  What volume of 0.716 M KBr solution is needed to provide 10.5 g of KBr? 21)   ______ 
A) 14.7 mL B)  123 mL C)  63.2 mL D)  7.52 mL 

22)  A solution is prepared by dissolving 171 g of CdCl2 in enough water to make exactly 250.0 mL of solution. If the density of the solution is 1.556 g/mL, what is the weight percent of CdCl2 in the solution? 22)   ______ 
A) 44.0% B)  56.0% C)  7.17% D)  68.4% 

The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent. 

23)  Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent? 23)   ______ 
A) Curve (b) is the solvent and the vapor pressure increases. 
B) Curve (a) is the solvent and the vapor pressure decreases. 
C) Curve (a) is the solvent and the vapor pressure increases. 
D) Curve (b) is the solvent and the vapor pressure decreases. 

24)  Which of the following mixtures have components which can be separated by filtration? 24)   ______ 
A) suspensions B)  solutions 
C) colloids D)  all of the above 

25)  What is the molality of a glucose solution prepared by dissolving .0 g of glucose, C6H12O6, in 125.9 g of water? 25)   ______ 
A)  m B)  0. m 
C)  m D)   þ 10- m 

26)  In most liquid solutions, the component present in the larger amount is called the 26)   ______ 
A) dispersed medium. B)  emulsifying agent. 
C) solvent. D)  solute. 

27)  What is the molality of a glucose solution prepared by dissolving 18.0 g of glucose, C6H12O6, in 125.9 g of water? 27)   ______ 
A) 0.794 m B)  0.143 m 
C) 7.94 þ 10-4 m D)  0.695 m 

28)  A 3.17 m solution of CaCl2 in water has a density of 1.24 g/mL. What is the molarity? 28)   ______ 
A) 3.93 M CaCl2 B)  2.56 M CaCl2 
C) 3.50 M CaCl2 D)  2.91 M CaCl2 

29)  Which of the following solutions will have the lowest freezing point? 29)   ______ 
A) 0.0100 m Li2SO4 B)  0.0100 m NaCl 
C) 0.035 m CH3CH2CH2OH D)  0.015 m MgCl2 

30)  Drawings (1) and (2) show the equilibrium vapor pressures of two pure liquids. Which drawing (3)-(6) represents the equilibrium vapor pressure of a solution made by mixing equal moles of each liquid?

 30)   ______ 
A) drawing (3) B)  drawing (4) C)  drawing (5) D)  drawing (6) 

31)  What is the approximate vapor composition above a boiling solution that is 0.70 XA and 0.30 XB ? 31)   ______ 
A) 0.70 XA, 0.30 XB B)  0.30 XA, 0.70 XB 
C) 0 XA, 1.00 XB D)  0.50 XA, 0.50 XB 

32)  For which case would DHsoln be expected to be negative? 32)   ______ 
A) if solvent-solvent interactions are much greater than solute-solvent and solute-solute interactions 
B) if solute-solvent interactions are much greater than solvent-solvent and solute-solute interactions 
C) if solute-solvent interactions are the same as solvent-solvent and solute-solute interactions 
D) if solute-solute interactions are much greater than solvent-solvent and solute-solvent interactions 

33)  Stainless steel is an example of a ________ solution. 33)   ______ 
A) solid/liquid B)  solid/solid 
C) liquid/liquid D)  gas/solid 

34)  When a particular solid begins to dissolve in water, the temperature rises dramatically. For the dissolving of this solid in pure water 34)   ______ 
A) DHsoln is always negative and DSsoln may be negative or positive. 
B) DHsoln is always positive and DSsoln is always positive. 
C) DHsoln is always negative and DSsoln is always positive. 
D) DHsoln is always positive and DSsoln may be negative or positive. 

35)  What molality of pentane is obtained by dissolving 5.0 g pentane, C5H12, in 245.0 g hexane, C6H14? 35)   ______ 
A) 0.024 m  B)  0.020 m C)  20. m D)  0.28 m 

36)  To make a  m solution, one could take  moles of solute and add  36)   ______ 
A) enough solvent to make 1.00 kg of solution. 
B) 1.00 kg of solvent. 
C) 1.00 L of solvent. 
D) enough solvent to make 1.00 L of solution. 

37)  KBr does not dissolve well in nonpolar solvents because 37)   ______ 
A) solute-solvent interactions are much larger than solvent-solvent or solute-solute interactions. 
B) solvent-solvent interactions are much larger than solute-solvent or solute-solute interactions. 
C) solute-solute interactions are much larger than solvent-solvent or solute-solvent interactions. 
D) solute-solvent interactions are similar to solvent-solvent and solute-solute interactions. 

Arrows in the energy diagram below represent enthalpy changes occurring in the endothermic formation of a solution:

	DHsoln = enthalpy of solution
	DHsolute-solute = enthalpy change involving solute-solute interactions
	DHsolute-solvent = enthalpy change involving solute-solvent interactions
	DHsolvent-solvent = enthalpy change involving solvent-solvent interactions

38)  Which arrow represents DHsolute-solvent? 38)   ______ 
A) arrow (a) B)  arrow (b) C)  arrow (c) D)  arrow (d) 

39)  A solution of LiCl in water has XLiCl = 0.000. What is the molality? 39)   ______ 
A)  m LiCl B)   m LiCl C)   m LiCl D)   m LiCl 

40)  At a given temperature the vapor pressures of benzene and toluene are 183 mm Hg and 59.2 mm Hg, respectively. Calculate the mole fraction of benzene in the vapor phase over a solution of benzene and toluene with Xbenzene = 0.600. 40)   ______ 
A) 0.600 B)  0.678 C)  0.823 D)  0.756 

41)  The following reaction is first order, C2H6 Â 2 CH3. If the rate constant is equal to 5.5 þ 10-4 s-1 at 1000 K, how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0. mol in the same container?  41)   ______ 
A)  min B)   min C)   min D)   min 

42)  The following reaction is first order in A and first order in B:
	A + B Â Products	Rate = k[A][B]
What is the rate constant k of this reaction in vessel (b) relative to the rate constant k of this reaction in vessel (a)? Each vessel has the same volume. Shaded spheres represent A molecules, and unshaded spheres represent B molecules.

 42)   ______ 
A) rate constant k in vessel (b)/rate constant k in vessel (a) = 1:2 
B) rate constant k in vessel (b)/rate constant k in vessel (a) = 4:1 
C) rate constant k in vessel (b)/rate constant k in vessel (a) = 1:1 
D) rate constant k in vessel (b)/rate constant k in vessel (a) = 2:1 

43)  The following reaction is second order in A and first order in B:
	A + B Â Products	Rate = k[A]2[B]
What is the initial rate of this reaction in vessel (b) relative to the initial rate of this reaction in vessel (a)? Each vessel has the same volume. Shaded spheres represent A molecules, and unshaded spheres represent B molecules present at the beginning of the reaction.

 43)   ______ 
A) rate in vessel (b)/rate in vessel (a) = 1:2 
B) rate in vessel (b)/rate in vessel (a) = 4:1 
C) rate in vessel (b)/rate in vessel (a) = 2:1 
D) rate in vessel (b)/rate in vessel (a) = 1:1 

44)  What is the activation energy for the destruction of ozone? 44)   ______ 
A) 406 kJ B)  14 kJ 
C) 392 kJ D)  none of these 

45)  The reaction for the decomposition of dinitrogen monoxide gas to form an oxygen radical is: . If the activation energy is 250 kJ/mol and the frequency factor is 8.0 þ 1011 s-1, what is the rate constant for the first-order reaction at 1000 K? 45)   ______ 
A) 9.1 þ 1024 s-1 B)  1.6 þ 1013 s-1 
C) 1.1 þ 10-3 s-1 D)  7.0 þ 10-2 s-1 

46)  The elementary reaction representing the formation of ozone:  is an example of a ________ reaction. 46)   ______ 
A) bimolecular B)  termolecular 
C) unimolecular D)  tetramolecular 

47)  Which statement below regarding the half-life of a zeroth-order reaction is true? 47)   ______ 
A) The half-life remains unchanged throughout the course of the reaction. 
B) Each half-life is four times as long as the preceding half-life. 
C) Each half-life is half as long as the preceding half-life. 
D) Each half-life is twice as long as the preceding half-life. 

48)  For a particular first-order reaction, it takes 48 minutes for the concentration of the reactant to decrease to 25% of its initial value. What is the value for rate constant (in s-1) for the reaction? 48)   ______ 
A) 2.9 þ 10-2 s-1 B)  6.0 þ 10-3 s-1 
C) 1.0 þ 10-4 s-1 D)  4.8 þ 10-4 s-1 

49)  Many secondary explosives commonly contain what two elements? 49)   ______ 
A) H and O B)  C and H C)  Hg and C D)  N and O 

50)  The following reaction is second order in A and first order in B:
	A + B Â Products	Rate = k[A]2[B]
What is the rate constant k of this reaction in vessel (b) relative to the rate constant k of this reaction in vessel (a)? Each vessel has the same volume. Shaded spheres represent A molecules, and unshaded spheres represent B molecules.

 50)   ______ 
A) rate constant k in vessel (b)/rate constant k in vessel (a) = 2:1 
B) rate constant k in vessel (b)/rate constant k in vessel (a) = 1:2 
C) rate constant k in vessel (b)/rate constant k in vessel (a) = 4:1 
D) rate constant k in vessel (b)/rate constant k in vessel (a) = 1:1 

51)  The following reaction is first order in A and first order in B:
	A + B Â Products	Rate = k[A][B]
What is the initial rate of this reaction in vessel (b) relative to the initial rate of this reaction in vessel (a)? Each vessel has the same volume. Shaded spheres represent A molecules, and unshaded spheres represent B molecules present at the beginning of the reaction.

 51)   ______ 
A) rate in vessel (b)/rate in vessel (a) = 1:1 
B) rate in vessel (b)/rate in vessel (a) = 2:1 
C) rate in vessel (b)/rate in vessel (a) = 1:2 
D) rate in vessel (b)/rate in vessel (a) = 4:1 

52)  Acetaldehyde decomposes at 750 K: CH3CHO Â CO + CH4. The reaction is first order in acetaldehyde and the half-life of the reaction is found to be 530 seconds. What is the rate constant for the reaction at this temperature? 52)   ______ 
A) 2.7 x 102 s-1 B)  7.6 x 102 s-1 
C) 1.3 x 10-3 s-1 D)  2.7 x 10-3 s-1 

53)  Which of the elementary reactions shown above has a molecularity of three? 53)   ______ 
A) elementary reaction (a) 
B) elementary reaction (b) 
C) elementary reaction (c) 
D) elementary reactions (a), (b), and (c) 

54)  Consider the first-order decompostion of A molecules (shaded spheres) in two vessels of equal volume.  How will the half-life of decomposition in vessel (a) be affected if the volume of the vessel is decreased by a factor of 2?

 54)   ______ 
A) increase by 4 B)  stay the same 
C) decrease by 1/2 D)  increase by 2 

55)  The rate constant, k, for a first-order reaction is equal to .2 þ 10-4 s-1. What is the half-life for the reaction?   55)   ______ 
A)  þ 10 s B)   þ 10 s C)   þ 103 s D)   þ 10-4 s 

56)  The following reaction is first order: C2H6 Â 2 CH3. If the rate constant is equal to 5.5 þ 10-4 s-1 at 1000 K, how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0.10 mol in the same container? 56)   ______ 
A) 7.6 min B)  131 min C)  106 min D)  38 min 

57)  The slowest step in a reaction mechanism is called the ________ step. 57)   ______ 
A) elementary B)  rate law 
C) activation D)  rate-determining 

58)  A plot of 1/[BrO-] vs time is linear for the reaction:
3 BrO-(aq) Â BrO3-(aq) + 2 Br-(aq)
What is the order of the reaction with respect to the hypobromite ion, BrO-? 58)   ______ 
A) 0 B)  1 C)  2 D)  3 

59)  A mechanism for a naturally occurring reaction that destroys ozone is:
	Step 1:  O3(g) + HO(g) Â HO2(g) + O2(g)
	Step 2:  HO2(g) + O(g) Â HO(g) + O2(g)
Which species is a catalyst and what type of catalysis is occuring? 59)   ______ 
A) HO2, homogeneous B)  HO2, heterogeneous 
C) HO, heterogeneous D)  HO, homogeneous 

60)  What is the overall reaction order for the reaction that has the rate law: Rate = k[][]?   60)   ______ 
A) zero order B)  first order 
C) second order D)  third order