CHEMISTRY 2202
JUNE 2002
INSTRUCTIONS: Select the BEST answer and SHADE in the appropriate space on the answer sheet
provided.
VALUE: 60%
1. A waste disposal firms adds excess aqueous sodium sulfide solution to an aqueous solution containing toxic mercury (II) chloride waste to produce solid mercury (II) sulfide and aqueous sodium chloride. An incorrect chemical formula in the chemical equation representing this reaction is
A. Na2S (aq)
B. HgCl2 (as
C. Hg2S (s) (Hg is 2+ and S 2- so cancels to HgS, not Hg2S)
D. NaCl (aq)
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Answer Questions 2 and 3 using the following information.
A student records the following evidence in a lab book:
Unknown Substance / Pure State / Solubility in Water / Solution ConductivityI / Solid / High / Low
II / Solid / Low / Low
III / Solid / High / None
IV / Solid / High / High
2. Which of the above substances exhibits the best evidence that it is a molecular compound?
A. I
B. II
C. III (moleculars do NOT conduct, their solubilites vary as d their solid states)
D. IV
3. Which substance best fits the description of Substance IV?
A. sucrose
B. glucose
C. barium hydroxide (Ionics conduct)
D. copper
4. Which period contains three elements that commonly exist as diatomic molecules?
A. Period 4
B. Period 5
C. Period 6
D. Period 7
5. Atoms of metallic elements tend to
A. gain electrons and form negative ions
B. gain electrons and form positive ions
C. lose electrons and form negative ions
D. lose electrons and form positive ions
6. An atom of an element with atomic number 50 and mass number 120 contains
A. 50 protons, 50 electrons, and 70 neutrons
B. 70 electrons, 50 protons, and 50 neutrons
C. 120 neutrons, 50 protons, and 70 electrons
D. 70 neutrons, 70 protons, and 50 electrons
7. What is true about the nucleus of an atom?
A. It is positively charged and has a high density.
B. It is positively charged and has a low density.
C. It is negatively charged and has a high density.
D. It is negatively charged and has a low density
8. Element X was found to have the following properties:
· It formed ionic compounds.
· It formed anions when bonded ionically.
· It formed a compound having an empirical formula, MbX2
What is the element, X, likely to be?
A. an alkali metal
B. a halogen
C. a group IIA element
D. a group VIA element
9. What is the percentage composition of carbon in acetone, C 3H6O (molar Mass = 58.09g/mol)?
A. 20.7%
B. 62.0% (36.03/58.09)
C. 1.61%
D. 30.0%
10. Which of these statements is NOT true?
A. Atoms of the same element can have different masses.
B. Atoms of isotopes of an element have different numbers of protons.
C. The nucleus of an atom has a positive charge.
D. Atoms are mostly empty space.
11. What is the ionic charge on the vanadium ion in the ionic compound vanadium oxide (V2O5)?
A. 2+
B. 2-
C. 5-
D. 5+
12. Consider an element Z that has two naturally occurring isotopes with the following percent abundances:
The isotope with a mass number of 20 is 25% abundant.
The isotope with a mass number of 22 is 75% abundant.
What is the average atomic mass for element Z?
A. 20.5 g
B. 21.5 g
C. 21.0 g
D. 42.0 g
13. The empirical formula of a compound is CH2F. The gram formula mass of this compound is 66.0 g. The molecular formula of the compound is:
A. C4H8F4
B. C4H4F4
C. C2H4F2
D. CH2F
14. The chemical formula of aspirin is C9H8O4 . What is the mass of 0.40 mol of aspirin?
A. 45 g
B. 10.8 g
C. 160 g
D. 72 g
15. How many moles of SO3 are in 2.4 x 1024 molecules of SO3?
A. 0.25
B. 3.4 x 1022
C. 4.0
D. 2.9 x 10-23
16. What is the volume (in liters at STP) of 2.50 mol of carbon monoxide?
A. 70 L
B. 3.1 L
C. 56 L
D. 9.0 L
17. Which element has the electron configuration, 2,8,7
A. Boron
B. Chlorine
C. Sodium
D. Lithium
18. Nitrogen boils at 77K. What is this temperature in degrees Celsius?
A. 350 degrees C
B. -350 degrees C
C. 196 degrees C
D. -196 degrees C
19. Which of the following changes is endothermic?
A. Digesting food
B. Melting ice.
C. Burning charcoal.
D. Explosion of dynamite.
20. Which of the following compounds is a strong electrolyte when dissolved in water?
A. CO2
B. KNO3
C. O2
D. C12H22O11
21. The white precipitate formed when aqueous solutions of BaCl2 and AgNO3 are mixed together is
A. Ba(NO3)2 (s)
B. Ag2Ba (s)
C. NClO3 (s)
D. AgCl (s)
22. In a reaction between HNO3 (aq) and NaOH (aq), the spectator ions are
A. H+ and Na+
B. H+ and OH—
C. Na+ and NO3—
D. OH—and NO3—
23. How many moles of carbon dioxide and required to completely react with 10 moles of FeO according to the equation:
3 FeO (s) + CO2 (g)à Fe3O4 (s) + CO (g)
A. 1.0
B. 3.3
C. 10
D. 30
24. How many grams of water are produced with 1.00 mole of oxygen reacts with ammonia according to the equation?
4 NH3 (g) + 5 O2 (g) à 4 NO (g) + 6 H2O (g)
A. 21.6 g
B. 27.0 g
C. 90.0 g
D. 108 g
25. A student carries out a reaction in which the theoretical yield of product is 22.4 g. She determines that she has a percent yield of 85.2 %. How many grams of product did she actually recover?
A. 19.1 g
B. 22.4 g
C. 26.3 g
D. 85.2 g
26. What is the number of valence electrons in an atom of beryllium?
A. 1
B. 2
C. 3
D. 4
27. The temperature at which the motion of particles theoretically ceases is:
A. -273 K
B. 0 K
C. O0 C
D. 273 0 C
28. As the temperature of a fixed volume of a gas increases, the pressure will:
A. vary inversely C. be unchanged
B. decrease D. increase
29. Which of the following is often used to aid in the understanding of the Quantum Mechanical Model of the atom?
A. Solar System
B. Rotating Fan
C. Billiard Ball
D. Raisin Bun
30. Which of these changes would NOT cause an increase in the pressure of a gaseous system?
A. The container is made larger.
B. Additional amounts of the same gas are added to the container.
C. The temperature is increased
D. Another gas is added to the container.
31. In a chemical analysis the reactant that is completely consumed is called the
A. excess reagent
B. limiting reagent
C. dissociation reagent
D. spectator reagent
32. The electron dot structure for an atom of nitrogen is:
A. N
B. N
C. N
D. N
33. If the pressure of a gas above a liquid is increased ( at constant temperature), the solubility of the gas in the liquid:
A. remains unchanged
B. increased
C. decreased
D. would be impossible to calculate
34. An ionic compound has a solubility of 30 grams per 100 mL of water at room temperature. A solution containing 80 grams of the compound in 250 mL of water at the same temperature:
A. saturated
B. supersaturated
C. unsaturated
D. a suspension
35. What is the percent (m/v) of 400 mL of a solution that contains 60 g of calcium chloride?
A. 1.35%
B. 15%
C. 24%
D. 6.7%
36. What is the concentration of 200 mL of solution in which 2.0 moles of sodium bromide is dissolved?
A. 2.0 mol/L
B. 10 mol/L
C. 0.40 mol/L
D. 4.0 mol/L
37. How many mL of alcohol are in 240 mL of 95.0% (v/v) alcohol solution?
A. 252 mL
B. 228 mL
C. 145 mL
D. 142 mL
38. How many nonbonding (lone) pairs of electrons are in a water molecule?
A. 1
B. 2
C. 3
D. 4
39. According to Lewis Theory (Lewis Dot), a possible compound of nitrogen and fluorine is
A. N3F B. NF2 C. N2F4 D. NF
40. Which substance, in the following table, can best be represented as a set of positive ions held together by a mobile pool of valence electrons?
Substance / Boiling Point (Celsius) / Solubility in Water / Electrical Conductivity of Solid1 / 2 212 / Low / High
2 / 78 / High / Low
3 / 2 590 / Low / Low
4 / -45 / Low / Low
A. 1 (metal) B. 2 C. 3 D. 4
41. Sucrose is dissolved in water to make cooking syrup. In this case, sucrose is the
A. Solute B. solution C. solvent D. catalyst
42. The shape of a molecule of CCl4 is
A. linear
B. tetrahedral
C. trigonal planar
D. pyramidal
43. Molality is defined as
A. moles of solute per kilogram of solution
B. grams of solute per 100 grams of solution
C. moles of solute per liter of solution
D. grams of solute per kilogram of solution
44. Which describes the shape of molecules of hydrogen sulfide?
A. linear
B. pyramidal
C. tetrahedral
D. V-shaped
45. Which substance has a definite shape and a definite volume at STP?
A. NaCl (aq)
B. Cl2 (g)
C. CCl4 (l)
D. AlCl3 (s) (SOLID)
46. Which is NOT a form of energy?
A. Light B. electricity C. temperature D. heat
47. Propane is widely used as a fuel. Consider the following reaction:
C3H8 (g) + 5 O2 à 3 CO2 (g) + 4 H2O (g)
If both gases are measured at the same temperature and pressure, the volume of oxygen required to react with 4.0 L of propane is
A. 0.80 L
B. 5.0 L
C. 20 L
D. 99 L
48. When sodium reacts with chlorine to form sodium chloride, electrons are lost by
A. sodium only
B. chlorine only
C. both sodium and chlorine
D. neither sodium nor chlorine
49. In which type of bond is there an equal attraction for the shared electrons by the bonded atoms?
A. ionic
B. metallic
C. polar covalent
D. nonpolar covalent
50. In his famous ‘gold foil experiment’, Ernest Rutherford encountered the
A. energy levels
B. electrons
C. nucleus
D. neutrons
51. A gas occupies a volume of 0.20 L at 10.0 kPa. What volume will the gas occupy at 100.0 kPa?
A. 0.02 L
B. 2.0 L
C. 20 L
D. 38 L
52. The volume of a helium balloon is 5.00 L indoors where the temperature is 27 0 C. Assuming no change in pressure, what volume will the helium occupy outdoors when it cools to –230C?
A. 4.17 L
B. 4.26 L
C. 5.87 L
D. 6.00 L
53. Determine the partial pressure of nitrogen in a mixture of gases if the total pressure is 93.4 kPa and the partial pressures of the other gases are: PHe = 26.7 kPa and Pne = 46.7 kPa.
A. 10.0 kPa
B. 20.0 kPa
C. 73.4 kPa
D. 101.3 kPa
54. What is the definition of London Dispersion Forces?
A. forces between the extra pairs of electrons on F, O or N and neighbouring molecules
B. forces that are stronger than ionic bonds
C. intramolecular forces of attraction which cause molecules to condense
D. the attraction for electrons in one molecule for the nuclei of atoms in neighbouring molecules
55. Which describes a solution that contains the maximum solute it can normally dissolve at a given temperature?
A. concentrated
B. dilute
C. saturated
D. supersaturated
56. The steps usually followed in preparing a solution of known concentration are:
1. measure out the required mass of solute
2. calculate the mass of solute required
3. add water to make up the total required volume of solution
4. dissolve the solute in less than the total volume of solvent required
A. 1 - 3 - 4 - 2
B. 2 - 1 - 4 - 3
C. 3 - 1 - 2 - 4
D. 4 - 1 - 2 - 3
57. One litre of a 0.010 mol/L solution of Ba(OH)2 (aq) was added to a solution containing 0.005 mol of Ca2+ (aq)
and a reaction occurred which may be represented by the equation
Ca2+ (aq) + 2 OH—(aq) à Ca(OH)2 (s) Ba(OH)2 (aq) supplies 2X as many OH or 0.020 moles OH, so 0.020 – 0.010 used in ppt = 0.010
0.005 needs 2/1 OH or 0.010
How much OH—(aq) remained in solution?
A. 0.001 mol