GEAS 1 - Chemistry_2

Excel Review Center 1.

What is the approximate forumula mass of Ca(NO3)2? A. B.

2.

B. C. D.

forms a precipitate forms a volatile product forms a sulfate salt and water forms a salt and water *

+2 +3

C. + 5 D. + 6 *

Upper right corner * Upper left corner Lower right corner Lower left corner

Which of the following pairs of compounds can be used t o illustrate the Law of Multiple Proportions. A. B. C. D.

9.

Dipole-dipole forces * Coordinate covalent bonding Covalent bonding Ionic bonding

Where are the highest ionization energies found in the periodic table? A. B. C. D.

8.

C. 9 D. 13 *

What is the oxidation number of sulfur in H2SO4 ? A. B.

7.

5 8

The reaction of of an acid like HCl and and a base like NaOH always A. B. C. D.

6.

are mixed with other molecules at lower temperature are frozen into a solid are heated to a higher temperature* temperature* collide with each other in a container at lower temperature

Which of the following is (are) the weakest attractive force? A. B. C. D.

5.

C. 164 * D. 180

How many atoms are represented in the formula Ca3(PO4)2? A. B.

4.

70 82

According to the Kinetic Molecular Theory, molecules increase in kinetic energy when they _________. A.

3.

ECE Refresher Course

5 10 *

16.3 32 *

C. 15 D. 20

C. 48 D. 64.3

11. 10 g of sodium hydroxide is dissolved dissolved in enough water to make 1.0 L of solution. What is the molarity of the solution? A. B.

0.25 M * 0.5 M

A. B.

0.5 L 1L*

A. B. C. D.

I. II.

CH2O and C4H6O4 CO and CO2 CH2 and C3 H6 * CH4 and C5 H12

III.

A. B.

14. When most most fuels burn, burn, the products include carbon dioxide and _____. A. B. C. D.

water * hydrogen hydrocarbons hydrogen peroxide

Cl H

A. B. C. D.

C. O D. He *

a covalent bond a polar covalent bond an ionic bond * a coordinate covalent bond

250 yrs 175 yrs

C. 100 yrs D. 200 ys *

3 4*

C. 1.5 M D. 1.75 M

22

46

C. 12.04x10 23 D. 6.02x10

H = 14.3%. If the formula mass of this gas is 42 amu, what are the empirical formula and the true formula? C. C2H4 ; C3H6 D. CH ; C4 H4

21. What fraction would be used to correct a given volume of gas at 30 degrees Celsius to its new volume when it is heated to 60 degrees Celsius and the pressure is kept constant? A. B.

273/333 373/333

C. 333/303 * D. 303/333

22. How many grams of NaOH are

needed to make 100 g of a 5% solution?

Baguio: PiRC Building, Gapuz Centrum II, 80 T. Alonso St., New Lucban CP: 0928 934 1637

C. I and III D. II and III

Alpha particle Beta particle * Proton Neutron

250 ml * 500 ml

C. 375 ml D. 425 ml

7 9

C. 11 D. 12 *

27. What volume of gas, in liters, would 1.5 1.5 mol of hydrogen occupy at STP? A. B.

A. B.

A. B. C.

of a gas have have C = 85.7% 85.7% and 20. Analysis of

CH2 ; C3H6 * C2H2 ; C3H6

I only * II only

26. How many atoms are present in the formula KAl(SO4)2?

D.

A. B.

Decrease the pressure with the temperature held constant Increase the pressure with temperature increase Increase the temperature with a pressure increase

22.4 L 33.6 L *

C. 44.8 L D. 67.2 L

2 8

C. 10 * D. 18

29. When excited excited electrons cascade to lower energy levels in an atom, _____________.

C. 5 D. 2

1.2x10 23 * 12.04x10

C. 20 g D. 40 g

28. What is the maximum number number of electrons held in the d orbitals?

18. What is the pH of an acetic acetic acid solution if the [H 3O] concentration is -14 1x10 mol/L? A. B.

A. B.

A. B.

17. If a radioactive element with with a half-life half-life of 100 years is found to have transmutated so that only 25% of the original sample remains, what is the age of the sample? A. B.

*

25. If you want to make make a dilute solution of 0.5 M NaCl and you have 250 ml of 1.0 M salt solution, how much water must be added to this solution t o achieve the 0.5 M concentration?

16. The complete loss of an electron of one one atom to another tom with the consequent formation of electrostatic charges is said to be _________. A. B. C. D.

2g 5g

24. Which of of the following particles particles has the least mass?

15. Which of of the following elements elements normally exists as a monoatomic molecule? A. B.

A. B.

23. Which of of the following will definitely cause the volume of a gas at STP to increase?

C. 1.5 L D. 2 L

13. Which formulas formulas could represent the empirical formula and the molecular formula of a given compound?

A. B.

10. If the density of a diatomic gas at at STP is is 1.43 g/L, what is its molar mass? A. B.

12. How much water, in liters, must must be added to 0.5 L of 6 M of HCl to make it 2 M?

19. 4 g of hydrogen gas at STP contain contain _________ _________ molecule molecules. s.

NO and NO2 * CH4 and CO2 NH3 and NH4Cl H2O and HCl

If 10 L of CO gas react with sufficient oxygen to completely react, h ow many liters of CO2 gas are formed? A. B.

GEAS Exam 1

Visible light is always emitted The potential energy of the atom increases The electrons always fall back to the first energy level The electrons fall back to lower unfilled energy level *

30. What is the boiling point point of water water at the top of a mountain 10,000 ft above sea level? A. B.

C.

D.

It is 100 degrees Celsius Less than 100 degrees Celsius since the pressure is less than at ground level * Less than 100 degrees Celsius since the pressure is greater t han at ground level More than 100 degrees Celsius since the pressure is greater t han at ground level

31. 5 liters of a gas at STP have a mass of of 12.5 g. What is the molar mass of the gas? Manila: CMFFI Bldg. R. Papa St. Tel. 7365291

Excel Review Center A. B.

56 g/mol * 125 g/mol

ECE Refresher Course C. 47.5 g/mol D. 12.5 g/mol

32. A compound whose molecular mass is 90 g contains 40% carbon, 6.67% hydrgren and 53.33% oxygen. W hat is the true formula of the compound? A. B.

C2H2O4 CH2O4

C. C3HO3 D. C3H6O3 *

33. To what volume, in ml, must 50 ml of 3.50 M of H2SO4 be diluted in order to make 2 M H2SO4? A. B.

25 ml 93.2 ml

C. 60.1 ml D. 87.5 ml *

34. A student measured 10 ml of an HCl solution into a beaker and titrated it with a standard NaOH solution that w as 0.09 M. The initial NaOH buret re ading was 34.7 ml while the final reading s howed 49.2 ml. What is the molarity of the HCl solution? A. B.

0.13 M * 0.47 M

C. 0.52 M D. 1.32 M

35. Find the percent composition of Cu in the compound CuSO4·5H2O A. B.

26% * 36%

C. 42% D. 49%

36. Given that a compound is composed of 60% Mg and 40% O, what is the empirical formula of the compound? A. B.

MgO * Mg2O

C. MgO2 D. MgO3

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

114 mmHg * 152 mmHg

24 g/mol 28 g/mol *

C. 32 g/mol D. 44 g/mol

39. How many grams of NaCl are needed to prepare 200 g of a 10% salt solution? A. B.

16 g 18 g

C. 20 g * D. 22 g

40. Suppose that a solution of hydrogen chloride gas dissolved in water has a concentration of 30% HCl by mass. How much solute is there in 100 ml of this solution if the specific gravity of the solution is 1.15? A. B.

22.4 g 34.5 g *

C. 40.5 g D. 45.5 g

41. Chemical action may involve all of the following except: A. B. C.

Combining of atoms of elements to form a molecule Separation of the molecules in a mixture * Breaking down compounds into elements

Reacting a compound and an element to form a new c ompound and a new element

42. Which of the following is an example of a physical change? A. B. C. D.

Fermenting of sugar to alcohol Rusting of iron * Burning of paper A solution of sugar in water

43. The electron-dot symbol consists of the symbol representing the element and an arrangement of dots that shows A. B. C. D.

The atomic number The atomic mass The number of neutrons The electrons in the outermost energy *

44. The lowest principal quantum number that an electron can have is ___. A. B.

0 1*

C. 2 D. 3

45. The sublevel that has only one orbital is identified by the letter _____. A. B.

S* P

C. D D. F

46. When 200 ml of a gas at constant pressure is heated, its volume ____. A. B. C. D.

Increases * Decreases Remains unchanged Can not be determined

A. B.

1.3 lb * 1.8 lb

C. 2.1 lb D. 2.5 lb

53. If you fill a 2-liter coke bottle at STP with carbon dioxide, how many particles does the coke bottle contain? A. B.

22

4.54x10 22 4.91x10

22

C. 5.37x10 * 22 D. 6.19x10

54. 44.8 liters of a gas are collected in a lab under constant conditions. The number of molecules in this volume is ____. A. B.

23

11x10 23 12x10 *

23

C. 13x10 23 D. 14x10

55. Solve for the number of atoms of carbon-14 that are in the average human body if carbon makes up 23 % of the human body by weight. The average human body has a mass of 150 kg. There are approximately 83 moles in every 1 kg of carbon. Also, 1 in every trillion atoms of carbon is carbon-14. A. B.

15

1.15x10 15 1.72x10 *

15

C. 2.11x10 15 D. 2.45x10

56. Air is composed of approximately 1.0% argon gas. How many liters of argon in a 58-g sample of air at ST P? A. B.

0.33 L * 0.39 L

C. 0.42 L D. 0.48 L

57. How many grams of sugar (C12 H22O11) can be crystallized from 250 ml of a 0.11 molar solution? A. B.

8.5 g 8.8 g

C. 9.4 g * D. 9.9 g

47. Graham’s Law refers to _________. A. B. C. D.

C. 392 mmHg D. 494 mmHg

38. At STP, what is the molar mass of a gas when the density is 1.25 g/L? A. B.

D.

GEAS Exam 1

boiling point of gases gaseous diffusion * gas compression problems volume changes of gases when the temperature changes

48. When oxygen combines with an element to form a compound, the resulting compound is called a(an) A. B.

salt oxidation

C. oxalate D. oxide *

49. The process of separating components of a mixture by making use of the difference in their boiling points is c alled ______. A. B. C. D.

Displacement Destructive distillation Fractional distillation * Filtration

50. When 200 ml of a gas at constant pressure is heated from 0 d egrees Celsius to 100 degrees Celsius, th e volume must be multiplied by ____. A. B.

273/100 100/273

C. 273/373 D. 373/273 *

51. Solve for the number of moles that make up 350 g of table salt, NaCl? A. B.

4 mol 5 mol

C. 6 mol * D. 7 mol

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


58. What is the molarity of 2.0 mol of NaCl in 0.872 L solution? A. B.

2.3 M * 2.8 M

C. 3.1 M D. 3.6 M

59. How many grams of solute are there in 671 ml of 2.0 M N aOH? A. B.

44 g 51 g

C. 54 g * D. 68 g

60. 50 g of potassium iodide is added to 1500 g of water. What is the molality of the resulting solution? A. B.

0.1m 0.2m *

C. 0.4m D. 0.5m

61. Calculate the molarity obtained by dissolving 102.9 g H3PO4 into 642 ml final volume of solution. A. B.

1.32M 1.44M

C. 1.64M * D. 1.88M

62. A 15.0M solution of ammonia has density of 0.90 g/ml. What is the mass percent of this solution? A. B.

22% 28% *

C. 34% D. 39%

63. 2.5g of glucose is dissolved into 375 ml of water. What is the molarity of the solution? A. B.

0.012M 0.037M *

C. 0.067M D. 0.081M

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Excel Review Center


64. How many grams of sodium chloride must you add to 750g of water to make a 0.35 molal solution? A. B.

7.59 g * 8.11 g

C. 8.89 g D. 9.42 g

65. What is the approximate percent composition of oxygen in magnesium oxide, MgO? A. B.

30% 35%

C. 40% * D. 45%

66. If 28.5 g of calcium hydroxide is dissolved in enough water to mak e 185 g of solution, calculate the percent concentration of calcium hydroxide in the solution? A. B.

11.7% 12.1%

C. 13.6% D. 15.4% *

67. Calculate the number of milliliters of 3.50 M ammonium carbonate solution necessary to provide 12.5 g of ammonium concentrate? A. B.

25.6 ml 28.9 ml

C. 31.1 ml D. 37.2 ml *

68. Calculate the mass at STP, in grams, of 230 ml of Cl2 gas at 20°C and 740 torr pressure. A. B.

0.444 g 0.581 g

C. 0.662 g * D. 0.714 g

69. What is the density of propane gas (C3H8) if the pressure of the gas was measured to be 3.5 atm at 285 K? A. B.

3.2 g/L 6.6 g/L *

C. 7.8 g/L D. 10.0 g/L

70. What would be the number of moles of chlorine gas present if the gas fills a 75ml flask having a pressure of 755 mmHg and a temperature of 100°C? A. B.

0.00112 0.00165

C. 0.00243 * D. 0.00411

71. Mystery Gas A effuses 4.0 times faster than oxygen. What is the likely identity of the Mystery Gas? A. B.

2 g/mol * 4 g/mol

C. 6 g/mol D. 8 g/mol

72. A container possesses 3 L internal volume. This volume is divided equally in two by a gas-tight seal. On one half of the seal, neon gas resides at 5 atm. The other half of the container is k ept under vacuum. Suddenly and with great fanfare, the internal seal is br oken. What is the final pressure of the container? A. B.

2.2 atm 2.5 atm *

C. 3.8 atm D. 4.1 atm

73. A red rubber dodge ball sits in a 20°C basement, filled with 3.50L of compressed air. Eager to begin practice of the impending dodge ball season, Vince reclaims the ball and takes it outside. After a few hours of practice, the well-sealed ball has a volume of 3.0L. What’s the temperature outside? A. B.

232 K 251 K *

GEAS Exam 1

74. A 0.80L container holds 10 mol of helium. The temperature of th e container is 10°C. W hat’s the internal pressure of the container? A. B.

220 atm 240 atm

C. 260 atm D. 290 atm *

75. The 0.80 L container from the example question breaks a seal. Because the container stored a poisonous gas, it was itself stored within a larger, vacuumsealed container. After the poisonous gas expands to fill th e newly available volume, the gas is at STP. What is the total volume of the secondary container? A. B.

224 L * 235 L

C. 256 L D. 280 L

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

0.8 atm 1.0 atm

C. 1.2 atm * D. 1.5 atm

815 g 840 g *

C. 860 g D. 920 g

3

78. A 5000-cm container holds 4.9 g of a gas when the pressure is 75 c m Hg and the temperature is 50°C. What will be the pressure if 6 g of this gas is confined 3 in a 2000 cm container at 0°C? A. B.

144 cmHg 151 cmHg

C. 167 cmHg D. 194 cmHg * 3

79. An automobile tire of volume 5.6x10 cc is filled with nitrogen t o a gauge pressure of 291 psi at room temperature 300 K. How much gas does the tire contain? A. B.

0.51 mol 0.68 mol *

C. 0.78 mol D. 0.91 mol

80. The pressure of the nitrogen in a constant-volume gas thermometer is 78 cm at 0°C. What is the temperature of a liquid in which the bulb of t he thermometer is immersed when the pressure is seen to be 87.7 cm? A. B.

144 K 282 K

C. 307 K * D. 440 K

81. Compute for the number of moles that is present in 84.5 L of a substance at STP. A. B.

3.77 mol * 3.99 mol

C. 4.56 mol D. 5.12 mol

82. Determine the empirical formula of a compound with a percent c omposition of 40% sulfur and 60% oxygen. A. B.

S2O3 SO

C. SO3 * D. SO4

C. 313 K D. 488 K


A. B.

OH H2O *

C. H3O D. HO2

84. What is the molecular formula of a compound which has a gram f ormula mass of 78 g/mol and the empirical formula NaO. A. B.

NaO Na2 O2 *

C. Na2 O3 D. Na3 O3

85. A molecular substance is 83.6% carbon and the remaining portion is hydrogen. Determine its molecular formula if the molar mass is about 172 g/m ol. A. B.

C3H7 C6H14

C. C9H21 D. C12H28 *

86. Calculate the percent composition of carbon in propane. A. B.

77. A volume of 50 liters is filled with helium at 15°C to a pr essure of 100 standard atmospheres. Assuming that the ideal gas equation is still approximately tr ue at this high pressure, c alculate approximately the mass of h elium required. A. B.

83. What is the empirical formula of a compound with a percent c omposition of 88.9% oxygen and 11.1% hydrogen.

81.8% * 18.2%

C. 69.9% D. 30.1%

87. Determine the pH given the following + -13 value: [H ] = 1x10 A. B.

1 5

C. 12 D. 13 *

88. Nitrogen comprised 78% of the air you are breathing. How fast are t he molecules of nitrogen running into the sides of your body at a room temperature of 25°C? A. B.

488 m/s 514 m/s *

C. 531 m/s D. 588 m/s

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

14.2 kg * 18.8 kg

C. 20.1 kg D. 24.4 kg

90. What is the average density of the Earth 6 if it has a radius of 6.38 x 10 m? A. B.

3.1 g/cc 3.4 g/cc

C. 5.5 g/cc * D. 6.1 g/cc

91. At 5 atm pressure and 70 degrees Celsius, how many moles are present in 1.5 L of oxygen gas? A. B.

0.036 1.60

C. 0.266 * D. 0.536

92. Distillation of water cannot remove ____________. A. B. C. D.

volatile liquids like alcohol * dissolved salts suspensions precipitates

93. A metallic oxide placed in water would most likely yield a(an) A. B. C. D.

Acid Base * Basic anhydride Metallic anhydride


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GEAS Exam 1

94. Small amount of solute is dispersed in the solvent: A. B. C. D.

Diluted solution * Concentrated solution Saturated solution Unsaturated solution

95. More solute can go into the solution at a certain temperature. This means that the solvent has further capacity t o hold more solute. This refers to what type of solution? A. B. C. D.

Diluted solution Concentrated solution Saturated solution Unsaturated solution *

96. This is a type of solution wherein the solution is holding all the s olute possible at a certain temperature. A. B. C. D.

Diluted solution Concentrated solution Saturated solution * Unsaturated solution

97. It refers to properties that are dependent primarily on the concentration of particles and not on the type of particle. A. B. C. D.

Intensive properties Concentrated properties Extensive properties Colligative properties *

98. A buffer solution ______________. A. B. C. D.

changes pH rapidly with the addition of an acid does not change pH at all resists changes in pH * changes pH only with the addition of a strong base

99. According to the Bronsted-Lowry Theory, an acid is a ____________. A. B. C. D.

proton donor * proton acceptor electron donor electron acceptor

100. The process of extracting aluminum is called _______. A. B. C. D.

The Dow process The Haber process The Hall process The Frasch process *



GEAS 1 - Chemistry_2

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