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Chemistry 1A Practice Test II 1. The melting point of nitrogen is 63 K. This temperature corresponds to [A] 63°C. [B] –63°C. [C] –210°C. [D] 483°C. [E] –336°C. 2. A given mass of gas occupies a volume of 4.00 L at 60°C and 550 mmHg. Which of the following mathematical expressions will yield its pressure at 3.00 L and 30°C?

[A] 5504 00300

3060

× ×..

[B] 5503004 00

3060

× ×..

[C] 5503004 00

333303

× ×..

[D] 5504 00300

303333

× ×..

[E] 5503004 00

303333

× ×..

3. How many moles of gas are in a gas sample occupying 0.250 L at 215 mmHg and 25°C? [A] 0.00217 [B] 0.00289 [C] 0.0345 [D] 0.416 [E] 1.27

4. At standard conditions, it was found that 1.17 L of a gas weighed 5.45 g. The gas is [A] NH3. [B] HNF2. [C] N2F4. [D] NH3. [E] NO2. 5. What volume of nitrous oxide, N2O, has the same number of ATOMS as 10.0 L of neon at the same temperature and pressure? [A] 1.67 L [B] 2.50 L [C] 3.33 L [D] 7.50 L [E] 10.0 L 6. Which of the following statements concerning equal volumes of the gases nitrogen(I) oxide, N2O, and propane, C3H8, at the same temperature and pressure, is (are) true? 1. They have the same number of atoms. 2. They have the same number of molecules. 3. They have the same density. [A] 1 only [B] 2 only [C] 1 and 2 only [D] 2 and 3 only [E] 1, 2, and 3 7. If ρ is the density of a gas, M its relative molecular mass, R the gas constant, T the temperature, and P its pressure, which of the following expressions represents the density of a gas?

[A] PMRT

[B] RMPT

[C] RMPT

[D] RTMP

[E] RTPM

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8. A sample of hydrogen was collected by water displacement at 23.0°C and an atmospheric pressure of 735 mmHg. Its volume is 568 mL. After water vapor is removed, what volume would the hydrogen occupy at the same conditions of pressure and temperature? (The vapor pressure of water at 23.0°C is 21 mmHg.) [A] 509 mL [B] 539 mL [C] 552 mL [D] 568 mL [E] 585 mL 9. Equal volumes (1.0 L) of ozone, O3, and methanethiol, CH3SH, under the same conditions have equal 1. numbers of molecules. 2. numbers of atoms. 3. masses. [A] 1 only [B] 2 only [C] 3 only [D] 1 and 2 only [E] 1 and 3 only 10. Real gases deviate from ideal behavior because of the attractive forces between the gas molecules and [A] ionization energies. [B] molecular vibrations. [C] pressures within the chemical bonds. [D] the molecules all having different velocities. [E] the actual volume of the molecules.

11. All the following are postulates of the kinetic-molecular theory of gases except [A] the collisions between molecules are elastic. [B] the gas molecules are in constant motion. [C] at a constant temperature, each molecule has the same kinetic energy. [D] the volumes of the molecules are negligible compared with the volume of the container. [E] the gas molecules are in rapid motion. 12. Which of the following statements is LEAST likely to be true of a sample of nitrogen gas? [A] Molecules of gaseous nitrogen are in constant random motion. [B] The pressure exerted by gaseous nitrogen is due to collisions of the molecules with the walls of the container. [C] The average kinetic energy of the gaseous nitrogen is proportional to the absolute temperature of the gas. [D] Collisions between the gaseous molecules are elastic. [E] The volume of the sample would be zero at –273°C.

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13. The molecular weight of an unknown gas was measured by an effusion experiment. It was found that it took 64 seconds for the gas to effuse, whereas nitrogen required 48 seconds. The molecular mass of the gas is [A] 16 g/mol. [B] 24 g/mol. [C] 30 g/mol. [D] 40 g/mol. [E] 50 g/mol. 14. From a consideration of the van der Waals constants for water and sulfur dioxide, a(atm • L / mol )2 2 b(L / mol)

H2O 5.54 0.0305 SO2 6.87 0.0568 we can conclude that [A] H2O molecules are smaller and less attracted to each other than SO2 molecules. [B] H2O molecules are smaller and more attracted to each other than SO2 molecules. [C] H2O molecules are larger and more attracted to each other than SO2 molecules. [D] H2O molecules are larger and less attracted to each other than SO2 molecules. [E] None of these conclusions is correct. 15. If ∆U = –65 kJ for a certain process, that process [A] occurs rapidly. [B] is exothermic. [C] is endothermic. [D] cannot occur. [E] requires a catalyst.

16. The sign of ∆H for the process CO2(s) → CO2(g) is [A] positive, and the process is endothermic. [B] negative, and the process is endothermic. [C] positive, and the process is exothermic. [D] negative, and the process is exothermic. [E] impossible to predict with confidence because ∆H f

o for CO2(s) and ∆H fo for CO2(g)

are not given. 17. Consider the following specific heats of metals. Metal Specific Heatcopper 0.385 Jmagnesium 1.02 Jmercury 0.138 J

silver 0.237 Jlead 0.129 J

(g C)(g C)

(g C)

(g C)(g C)

• °• °

• °• °• °

If the same amount of heat is added to 25.0 g of each of the metals, which are all at the same temperature, which metal will have the highest temperature? [A] copper [B] magnesium [C] mercury [D] silver [E] lead 18. The sign of ∆H for the process NaCl(s) → NaCl(l) is [A] negative, and the process is endothermic. [B] positive, and the process is exothermic. [C] positive, and the process is endothermic. [D] negative, and the process is exothermic. [E] impossible to predict because ∆H f

o for NaCl(s) and ∆H f

o for NaCl(l) are not given.

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19. Which of the following would be needed to determine the energy of combustion of ethanol in a bomb calorimeter? 1. temperature increase 2. amount of ethanol 3. heat capacity of calorimeter [A] 1 only [B] 1 and 2 only [C] 1 and 3 only [D] 2 and 3 only [E] 1, 2, and 3 20. When 0.0500 mol of HCl is reacted with 0.0500 mol of NaOH in 50.0 mL of water, the temperature of the water increases by 13.7°C. Calculate the heat of the reaction for the following thermochemical equation: HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) Assume that the heat capacity of the system is 209.2 J/°C. [A] –57,300 J/mol [B] –2870 J/mol [C] + 2870 J/mol [D] +57,300 J/mol [E] +115,000 J/mol 21. All the following are state functions EXCEPT [A] w. [B] H. [C] U. [D] P. [E] T. 22. What is the quantity of heat evolved when 200. g H2O(l) is formed from the combustion of H2(g) and O2(g)?

H2(g) + 12

O2(g) → H2O(l) ∆H° = –

285.8 kJ

[A] 285.8 kJ [B] 1590 kJ [C] 3170 kJ [D] 4360 kJ [E] 57200 kJ 23. Calculate the change in enthalpy when 52.0 g of Cr at 25°C and 1 atm pressure is oxidized. (∆H f

o for Cr2O3(s) is –1140 kJ/mol.) 4Cr(s) + 3O2(g) → 2Cr2O3(s) [A] –1140 kJ [B] +1140 kJ [C] –570 kJ [D] +570 kJ [E] –285 kJ 24. Which substance has a heat of formation equal to zero at 25°C and 1 atm? [A] C2H6(g) [B] C2H6(l) [C] Br2(s) [D] Br2(l) [E] Br2(g) 25. All the following statements are true for an exothermic reaction EXCEPT [A] the temperature of the reaction system increases. [B] the temperature of the surroundings increases. [C] heat passes from the reaction system to the surroundings. [D] the products have a higher heat content than the reactants. [E] the enthalpy change for the reaction is negative.

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26. The equation for the standard enthalpy of formation of potassium bromate, KBrO3, corresponds to which reaction? [A] K(s) + 1

2 Br2(g) + 32 O2(g) →

KBrO3(s) [B] K(g) + 1

2 Br2(g) + 32 O2(g) →

KBrO3(s) [C] K(s) + 1

2 Br2(l) + 32 O2(g) →

KBrO3(s) [D] K(g) + Br(g) + 3O(g) → KBrO3(s) [E] K(s) + Br(g) + 3O(g) → KBrO3(s) 27. Given the following data,

∆H kJ molS ) + O SOS ) + O SO

2

2

° → − → −

( )( ( ) ( )( ( ) ( )s g gs g g

2

2

395618

find the heat required for the reaction converting solid sulfur to gaseous sulfur at 298 K and 1 atm pressure. [A] –1013 kJ/mol [B] +618 kJ/mol [C] –618 kJ/mol [D] –223 kJ/mol [E] +223 kJ/mol 28. Given the following data:

N O N O H kJ

N O 2NO(g) H kJ12

N O NO H kJ

2 2 2 3

2 2

2 2 2

( ) ( ) ( ) .

( ) ( ) .

( ) ( ) ( ) .

g g s

g g

g g g

+ → =

+ → =

+ → =

32

837

180 4

332

∆

∆

∆

what is ∆H for the reaction N2O3(g) → NO(g) + NO2(g) [A] –207.1 kJ [B] –39.7 kJ [C] 24.3 kJ [D] 39.7 kJ [E] 207.1 kJ

29. Using the following data, determine the heat of reaction for the combustion of 1 mol of ethylene, C2H4. C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(l) Compound H (kJ / mol)C H ( ) + 52.3CO ( ) 393.5H O( ) 285.9

f

2 4

2

2

∆ °

−−

g

g

l

[A] +731.4 kJ [B] +1411.1 kJ [C] –1411.1 kJ [D] –1306.5 kJ [E] +1306.5 kJ 30. Given the following data at 25°C and 1.00 atm pressure:

Pb( ) + PbO ( ) + 2H SO ( ) 2PbSO ( ) + 2H O( )SO ( ) + H O( ) H SO ( )

2 2 4 4 2

3 2 2 4

→ →

s s l s lg l l

evaluate ∆H° for the reaction below at 25°C. Pb(s) + PbO2(s) + 2SO3(g) → 2PbSO4(s) [A] –3.77 × 103 kJ [B] 3.77 × 103 kJ [C] –639 kJ [D] –521 kJ [E] –769 kJ 31. All of the following statements are TRUE EXCEPT [A] the value of q is positive when heat flows into a system from the surroundings. [B] heat flows from a system into the surroundings in an endothermic process. [C] enthalpy is a state property. [D] energy is a state property. [E] the value of q is positive in an endothermic process.

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32. Rank the following regions of the electromagnetic spectrum in order of decreasing energy. X-rays, Microwaves, Infrared, Ultraviolet [A] x-rays, microwaves, infrared, ultraviolet [B] microwaves, ultraviolet, infrared, x-rays [C] microwaves, infrared, ultraviolet, x-rays [D] infrared, microwaves, ultraviolet, x-rays [E] x-rays, ultraviolet, infrared, microwaves 33. What is the wavelength of light associated with the radiation of 7 26 10 19. × − J / photon?

h J s.= × •−6 63 10 34.� � [A] 137 nm [B] 231 nm [C] 274 nm [D] 548 nm [E] 684 nm 34. What is the wavelength of light emitted when the hydrogen atom undergoes a transition from level n = 5 to level n = 2? R JH = × −2180 10 18. [A] 663 nm [B] 833 nm [C] 546 nm [D] 521 nm [E] 434 nm 35. Einstein’s work on the photoelectric effect made extensive use of the equation [A] E = mc2. [B] υ = c/λ

[C] E = − Rn

H2

.

[D] E = hυ.

[E] ∆E = R 1n n

.H22

12− −

���

���

1

36. The contribution for which de Broglie is remembered in modern science is [A] his statement that an electron can exist in an atom only in discrete energy levels. [B] his statement that no electron can have identical values for all four quantum numbers. [C] his proposal that particles of matter should be associated with wavelike behavior. [D] his statement that elements show periodic repetition of properties. [E] his statement that electrons occupy all the orbitals of a given sublevel singly before pairing begins. 37. Which of the following combinations of quantum numbers are permissible?

n l m ml s

1 3 3 1 1 22 4 3 0 1 2

3 3 2 1 1 2

. /. /

. /

−−+

[A] 1 only [B] 2 only [C] 3 only [D] 1 and 2 only [E] 2 and 3 only 38. What orbital has the quantum numbers n = 4, l = 3, m1 = –1? [A] s [B] p [C] d D] f E] g 39. Which one of the orbital occupancy designations shown below does NOT make sense? [A] 2s1 [B] 3d10 [C] 4p7

[D] 4f7

[E] 2p6

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40. The maximum number of electrons in a 4d subshell is [A] 1.1[B] 3. [C] 5. [D] 8. [E] 10. 41. The angular momentum quantum number of the first two valence electrons in an atom of lead is [A] 1. [B] 2. [C] 3. [D] 4. E] 5. 42. The maximum number of 5d electrons is [A] 10. [B] 7. [C] 5. [D] 4. [E] 3. 43. An element that has the same valence electron configuration as tin is [A] antimony. [B] tellurium. [C] indium. [D] selenium. [E] germanium. 44. Which of the following orbital diagrams is IMPOSSIBLE according to the Pauli exclusion principle?

[A] Option 1 [B] Option 2 [C] Option 3 [D] Option 4 [E] Option 5

45. Which of the following electron configurations represents an excited state? [A] He: 1s2

[B] Ne: 1s2 2s2 2p6

[C] Na: 1s2 2s2 2p6 3s2 3p2 4s1

[D] P: 1s2 2s2 2p6 3s2 3p2 4s1

[E] N: 1s2 2s2 2p3

46. The elements that are filling the 5f subshell is (are) called 1. lanthanides. 2. inner transition elements. 3. actinides. [A] 1 only [B] 2 only [C] 3 only [D] 1 and 2 only [E] 2 and 3 only 47. The formula that one would expect for calcium nitride is [A] Ca3N2. [B] Ca2N3. [C] CaNO2. [D] Ca(NO2)2. [E] Ca(NO3)2. 48. Which of the following atoms has the LARGEST atomic radius? [A] Sr [B] Mg [C] P [D] I [E] Kr

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49. Which of the following atoms designated by electronic configurations has the highest ionization energy? [A] [Ne] 3s2 3p2

[B] [Ne] 3s2 3p3

[C] [Ar] 3d10 4s2 4p3

[D] [Kr] 4d10 5s2 5p3

[E] [Xe] 4f14 5d10 6s2 6p3

50. Which one of the following elements would be expected to have the SMALLEST atomic radius? [A] Li [B] Cs [C] F [D] Br [E] I 51. Which of the following atoms has the most negative electron affinity? [A] Na [B] Cl [C] Br [D] S [E] As 52. When arranged in order of increasing atomic number, the elements exhibit periodicity for all the following properties EXCEPT [A] ionization energy. [B] atomic radii. [C] electron configurations. [D] electron affinity. [E] atomic masses.

53. Which of the following equations represents the first ionization energy of calcium? [A] Ca(s) → Ca+(s) + e-

[B] Ca(s) + e- → Ca-(s) [C] Ca(g) → Ca+(g) + e-

[D] Ca(s) → Ca+(g) + e-

[E] Ca(g) → Ca2+(g) + 2e-

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ANSWERS [1] [C] [2] [D] [3] [B] [4] [C] [5] [C] [6] [D] [7] [A] [8] [C] [9] [E] [10] [E] [11] [C] [12] [E] [13] [E] [14] [A] [15] [B] [16] [A] [17] [E] [18] [C] [19] [E] [20] [A] [21] [A] [22] [C] [23] [C] [24] [D] [25] [D] [26] [C] [27] [E] [28] [D] [29] [C] [30] [E] [31] [B] [32] [E] [33] [C] [34] [E] [35] [D] [36] [C] [37] [E] [38] [D] [39] [C] [40] [E] [41] [A]

[42] [A] [43] [E] [44] [B] [45] [D] [46] [E] [47] [A] [48] [A] [49] [B] [50] [C] [51] [B] [52] [E] [53] [C]