geas 1 - chemistry_2

8/13/2019 GEAS 1 - Chemistry_2

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Excel Review Center ECE Refresher Course GEAS Exam 1

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A. 56 g/mol * C. 47.5 g/molB. 125 g/mol D. 12.5 g/mol

32. A compound whose molecular mass is90 g contains 40% carbon, 6.67%hydrgren and 53.33% oxygen. What isthe true formula of the compound?

A. C 2H2O4 C. C 3HO 3

B. CH 2O4 D. C 3H6O3 *

33. To what volume, in ml, must 50 ml of3.50 M of H 2SO 4 be diluted in order tomake 2 M H 2SO 4?

A. 25 ml C. 60.1 mlB. 93.2 ml D. 87.5 ml *

34. A student measured 10 ml of an HClsolution into a beaker and titrated it witha standard NaOH solution that was 0.09M. The initial NaOH buret reading was34.7 ml while the final reading showed49.2 ml. What is the molarity of the HClsolution?

A. 0.13 M * C. 0.52 MB. 0.47 M D. 1.32 M

35. Find the percent composition of Cu inthe compound CuSO 4·5H 2O

A. 26% * C. 42%B. 36% D. 49%

36. Given that a compound is composed of60% Mg and 40% O, what is theempirical formula of the compound?

A. MgO * C. MgO 2

B. Mg 2O D. MgO 3

37. A mixture of gases at 760 mm Hgpressure contains 65% nitrogen, 15%oxygen and 20% carbon by volume.What is the partial pressure of oxygengas?

A. 114 mmHg * C. 392 mmHgB. 152 mmHg D. 494 mmHg

38. At STP, what is the molar mass of a gaswhen the density is 1.25 g/L?

A. 24 g/mol C. 32 g/molB. 28 g/mol * D. 44 g/mol

39. How many grams of NaCl are needed toprepare 200 g of a 10% salt solution?

A. 16 g C. 20 g * B. 18 g D. 22 g

40. Suppose that a solution of hydrogenchloride gas dissolved in water has aconcentration of 30% HCl by mass. Howmuch solute is there in 100 ml of thissolution if the specific gravity of thesolution is 1.15?

A. 22.4 g C. 40.5 gB. 34.5 g * D. 45.5 g

41. Chemical action may involve all of thefollowing except:

A. Combining of atoms of elements toform a molecule

B. Separation of the molecules in amixture *

C. Breaking down compounds intoelements

D. Reacting a compound and anelement to form a new compoundand a new element

42. Which of the following is an example ofa physical change?

A. Fermenting of sugar to alcoholB. Rusting of iron *

C. Burning of paperD. A solution of sugar in water

43. The electron-dot symbol consists of thesymbol representing the element and anarrangement of dots that shows

A. The atomic numberB. The atomic massC. The number of neutronsD. The electrons in the outermost

energy *

44. The lowest principal quantum numberthat an electron can have is ___.

A. 0 C. 2B. 1 * D. 3

45. The sublevel that has only one orbital isidentified by the letter _____.

A. S * C. DB. P D. F

46. When 200 ml of a gas at constantpressure is heated, its volume ____.

A. Increases * B. DecreasesC. Remains unchanged

D. Can not be determined

47. Graham’s Law refers to _________.

A. boiling point of gasesB. gaseous diffusion * C. gas compression problemsD. volume changes of gases when the

temperature changes

48. When oxygen combines with an elementto form a compound, the resultingcompound is called a(an)

A. salt C. oxalateB. oxidation D. oxide *

49. The process of separating componentsof a mixture by making use of thedifference in their boiling points is c alled

______.

A. DisplacementB. Destructive distillationC. Fractional distillation * D. Filtration

50. When 200 ml of a gas at constantpressure is heated from 0 degreesCelsius to 100 degrees Celsius, thevolume must be multiplied by ____.

A. 273/100 C. 273/373B. 100/273 D. 373/273 *

51. Solve for the number of moles thatmake up 350 g of table salt, NaCl?

A. 4 mol C. 6 mol * B. 5 mol D. 7 mol

52. Solve for the mass of 3 moles ofplatinum in pounds.

A. 1.3 lb * C. 2.1 lbB. 1.8 lb D. 2.5 lb

53. If you fill a 2-liter coke bottle at STP withcarbon dioxide, how many particlesdoes the coke bottle contain?

A. 4.54x10 22 C. 5.37x10 22 * B. 4.91x10 22 D. 6.19x10 22

54. 44.8 liters of a gas are collected in a labunder constant conditions. The numberof molecules in this volume is ____.

A. 11x10 23 C. 13x10 23 B. 12x10 23 * D. 14x10 23

55. Solve for the number of atoms ofcarbon-14 that are in the averagehuman body if carbon makes up 23% ofthe human body by weight. The averagehuman body has a mass of 150 kg.There are approximately 83 moles inevery 1 kg of carbon. Also, 1 in everytrillion atoms of carbon is carbon-14.

A. 1.15x10 15 C. 2.11x10 15 B. 1.72x10 15 * D. 2.45x10 15

56. Air is composed of approximately 1.0%argon gas. How many liters of argon in a58-g sample of air at STP?

A. 0.33 L * C. 0.42 LB. 0.39 L D. 0.48 L

57. How many grams of sugar (C 12 H22 O11 )can be crystallized from 250 ml of a 0.11molar solution?

A. 8.5 g C. 9.4 g * B. 8.8 g D. 9.9 g

58. What is the molarity of 2.0 mol of NaClin 0.872 L solution?

A. 2.3 M * C. 3.1 MB. 2.8 M D. 3.6 M

59. How many grams of solute are there in671 ml of 2.0 M NaOH?

A. 44 g C. 54 g * B. 51 g D. 68 g

60. 50 g of potassium iodide is added to1500 g of water. What is the molality ofthe resulting solution?

A. 0.1m C. 0.4mB. 0.2m * D. 0.5m

61. Calculate the molarity obtained bydissolving 102.9 g H 3PO 4 into 642 mlfinal volume of solution.

A. 1.32M C. 1.64M * B. 1.44M D. 1.88M

62. A 15.0M solution of ammonia hasdensity of 0.90 g/ml. What is the masspercent of this solution?

A. 22% C. 34%B. 28% * D. 39%

63. 2.5g of glucose is dissolved into 375 mlof water. What is the molarity of thesolution?

A. 0.012M C. 0.067MB. 0.037M * D. 0.081M





64. How many grams of sodium chloridemust you add to 750g of water to makea 0.35 molal solution?

A. 7.59 g * C. 8.89 gB. 8.11 g D. 9.42 g

65. What is the approximate percentcomposition of oxygen in magnesium

oxide, MgO?

A. 30% C. 40% * B. 35% D. 45%

66. If 28.5 g of calcium hydroxide isdissolved in enough water to make 185g of solution, calculate the percentconcentration of calcium hydroxide inthe solution?

A. 11.7% C. 13.6%B. 12.1% D. 15.4% *

67. Calculate the number of milliliters of3.50 M ammonium carbonate solutionnecessary to provide 12.5 g ofammonium concentrate?

A. 25.6 ml C. 31.1 mlB. 28.9 ml D. 37.2 ml *

68. Calculate the mass at STP, in grams, of230 ml of Cl 2 gas at 20°C and 740 torrpressure.

A. 0.444 g C. 0.662 g * B. 0.581 g D. 0.714 g

69. What is the density of propane gas(C 3H8) if the pressure of the gas was

measured to be 3.5 atm at 285 K?

A. 3.2 g/L C. 7.8 g/LB. 6.6 g/L * D. 10.0 g/L

70. What would be the number of moles ofchlorine gas present if the gas fills a 75-ml flask having a pressure of 755 mmHgand a temperature of 100°C?

A. 0.00112 C. 0.00243 * B. 0.00165 D. 0.00411

71. Mystery Gas A effuses 4.0 times fasterthan oxygen. What is the likely identityof the Mystery Gas?

A. 2 g/mol * C. 6 g/molB. 4 g/mol D. 8 g/mol

72. A container possesses 3 L internalvolume. This volume is divided equallyin two by a gas-tight seal. On one half ofthe seal, neon gas resides at 5 atm. Theother half of the container is k ept undervacuum. Suddenly and with greatfanfare, the internal seal is broken. Whatis the final pressure of the container?

A. 2.2 atm C. 3.8 atmB. 2.5 atm * D. 4.1 atm

73. A red rubber dodge ball sits in a 20°Cbasement, filled with 3.50L ofcompressed air. Eager to begin practiceof the impending dodge ball season,Vince reclaims the ball and takes itoutside. After a few hours of practice,the well-sealed ball has a volume of3.0L. What’s the temperature outside?

A. 232 K C. 313 KB. 251 K * D. 488 K

74. A 0.80L container holds 10 mol ofhelium. The temperature of thecontainer is 10°C. What’s the internalpressure of the container?

A. 220 atm C. 260 atmB. 240 atm D. 290 atm *

75. The 0.80 L container from the example

question breaks a seal. Because thecontainer stored a poisonous gas, it wasitself stored within a larger, vacuum-sealed container. After the poisonousgas expands to fill the newly availablevolume, the gas is at STP. What is thetotal volume of the secondarycontainer?

A. 224 L * C. 256 LB. 235 L D. 280 L

76. What is the total pressure inside acontainer that contains He at a pressureof 0.45 atm and Ar at a pressure of 0.75atm?

A. 0.8 atm C. 1.2 atm * B. 1.0 atm D. 1.5 atm

77. A volume of 50 liters is filled with heliumat 15°C to a pressure of 100 standardatmospheres. Assuming that the idealgas equation is still approximately trueat this high pressure, calculateapproximately the mass of heliumrequired.

A. 815 g C. 860 gB. 840 g * D. 920 g

78. A 5000-cm3

container holds 4.9 g of agas when the pressure is 75 cm Hg andthe temperature is 50°C. What will bethe pressure if 6 g of this gas is confinedin a 2000 cm 3 container at 0°C?

A. 144 cmHg C. 167 cmHgB. 151 cmHg D. 194 cmHg *

79. An automobile tire of volume 5.6x10 3 ccis filled with nitrogen to a gaugepressure of 291 psi at room temperature300 K. How much gas does the tirecontain?

A. 0.51 mol C. 0.78 molB. 0.68 mol * D. 0.91 mol

80. The pressure of the nitrogen in aconstant-volume gas thermometer is 78cm at 0°C. What is the temperature of aliquid in which the bulb of thethermometer is immersed when thepressure is seen to be 87.7 cm?

A. 144 K C. 307 K * B. 282 K D. 440 K

81. Compute for the number of moles that ispresent in 84.5 L of a substance at STP.

A. 3.77 mol * C. 4.56 molB. 3.99 mol D. 5.12 mol

82. Determine the empirical formula of acompound with a percent composition of40% sulfur and 60% oxygen.

A. S 2O3 C. SO 3 * B. SO D. SO 4

83. What is the empirical formula of acompound with a percent composition of88.9% oxygen and 11.1% hydrogen.

A. OH C. H 3OB. H 2O * D. HO 2

84. What is the molecular formula of acompound which has a gram formula

mass of 78 g/mol and the empiricalformula NaO.

A. NaO C. Na 2O3 B. Na 2O2 * D. Na 3O3

85. A molecular substance is 83.6% carbonand the remaining portion is hydrogen.Determine its molecular formula if themolar mass is about 172 g/mol.

A. C 3H7 C. C 9H21 B. C 6H14 D. C 12 H28 *

86. Calculate the percent composition ofcarbon in propane.

A. 81.8% * C. 69.9%B. 18.2% D. 30.1%

87. Determine the pH given the followingvalue: [H +] = 1x10 -13

A. 1 C. 12B. 5 D. 13 *

88. Nitrogen comprised 78% of the air youare breathing. How fast are themolecules of nitrogen running into thesides of your body at a roomtemperature of 25°C?

A. 488 m/s C. 531 m/sB. 514 m/s * D. 588 m/s

89. A piece of machinery can beconstructed from steel (ρ = 7.8 g/cc) orfrom a magnesium- aluminum allow (ρ =2.4 g/cc). When steel is used, the massof the piece is 46 kg. What would be themass if the allow were used?

A. 14.2 kg * C. 20.1 kgB. 18.8 kg D. 24.4 kg

90. What is the average density of the Earthif it has a radius of 6.38 x 10 6 m?

A. 3.1 g/cc C. 5.5 g/cc * B. 3.4 g/cc D. 6.1 g/cc

91. At 5 atm pressure and 70 degreesCelsius, how many moles are present in1.5 L of oxygen gas?

A. 0.036 C. 0.266 * B. 1.60 D. 0.536

92. Distillation of water cannot remove ____________.

A. volatile liquids like alcohol * B. dissolved saltsC. suspensionsD. precipitates

93. A metallic oxide placed in water wouldmost likely yield a(an)

A. AcidB. Base * C. Basic anhydrideD. Metallic anhydride





94. Small amount of solute is dispersed inthe solvent:

A. Diluted solution * B. Concentrated solutionC. Saturated solutionD. Unsaturated solution

95. More solute can go into the solution at a

certain temperature. This means thatthe solvent has further capacity to holdmore solute. This refers to what type ofsolution?

A. Diluted solutionB. Concentrated solutionC. Saturated solutionD. Unsaturated solution *

96. This is a type of solution wherein thesolution is holding all the solute possibleat a certain temperature.

A. Diluted solutionB. Concentrated solutionC. Saturated solution * D. Unsaturated solution

97. It refers to properties that are dependentprimarily on the concentration ofparticles and not on the type of particle.

A. Intensive propertiesB. Concentrated propertiesC. Extensive propertiesD. Colligative properties *

98. A buffer solution ______________.

A. changes pH rapidly with the

addition of an acidB. does not change pH at allC. resists changes in pH * D. changes pH only with the addition

of a strong base

99. According to the Bronsted-LowryTheory, an acid is a ____________.

A. proton donor * B. proton acceptorC. electron donorD. electron acceptor

100. The process of extracting aluminum iscalled _______.

A. The Dow processB. The Haber processC. The Hall processD. The Frasch process *

geas 1 - chemistry_2

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