General Chemistry Review

1. How many moles of chlorine gas are contained in 9.02 * 1023 molecules?
   1.5 moles
2. When a metal is heated in a flame, the flame has a distinctive color.  This information was eventually extended to the study of stars because -
   the color spectra of stars indicate with elements are present.
3. Some of the molecules found in the human body are NH2CH2COOH (glycine), C6H12O6 (glucose), and CH3(CH2)16COOH (stearic acid.).  The bonds they form are
   covalent
4. Electrical fires cannot be safely put out by dousing them with water.  However, fire extinguishers that spray solid carbon dioxide on the fire work very effectively.  This method works because carbon dioxide
   displaces the oxygen
5. Mg3N2 (s) + 6 H2O (l) → 2 NH3 (aq) + 3 Mg(OH)2 (s)
   If 54.0 grams of water are mixed with excess magnesium nitride, then how many grams of ammonia are produced?
   17.0 grams
6. Which of the following is a monatomic gas at STP?
   Helium
7. The boiling point of liquid nitrogen is 77 kelvin.  It is observed that ice forms at the opening of a container of liquid nitrogen.  The best explanation for this observation is
   the water vapor in the air over the opening of the liquid nitrogen freezes.
8. When cations and anions join, they form what kind of chemical bond? ionic
9. NO2 (g) + CO (g) ↔ NO (g) + CO2 (g) The reaction shown above occurs inside a closed flask.  What action will shift the reaction to the left?
   Increasing the NO concentration in the flask.
10. Which substance is made up of many monomers joined together in long chains?
    protein
11. In order to advance to the level of a theory, a hypothesis should be
    repeatedly confirmed by experimentation.
12. Of four different laboratory solutions, the solution with the highest acidity has a pH of 3
13. 4 HCl (g) + O2 (g) ↔ 2 H2O (l) + 2 Cl2 (g) + 113 kJ Which action will drive the reaction to the right?
    increasing the system’s pressure
14. A weather balloon with a 2-meter diameter at ambient temperature holds 525 grams of helium.  What type of electronic probe could be used to determine the pressure inside the balloon?
    barometric
15. Under which of the following sets of conditions will a 0.50 mole sample of helium occupy a volume of 11.2 liters?
    273 K and 1.00 atm
16. The volume of 400 mL of chlorine gas at 400 mm Hg is decreased to 200 mL at constant temperature.  What is the new gas pressure?
    800 mm Hg
17. H2O2, hydrogen peroxide, naturally breaks down into H2O and O2 over time.  MnO2, manganese(IV) oxide, can be used to lower the energy of activation needed for this reaction to take place and, thus, increase the rate of reaction.  What type of substance is MnO2?
    catalyst
18. Which of these is an example of an exothermic chemical process?
    combustion of gasoline
19. Which equation correctly represents the alpha decay of polomnium-214? C
20. When a reaction is at equilibrium and more reactant is added, which of the following changes is the immediate result?
    the forward reaction rate increases
21. Theoretically, when an ideal gas in a closed container cools, the pressure will drop steadily until the pressure inside is essentially that of a vacuum.  At what temperature should this occur?
    0 K
22. Which statement best describes the density of an atom's nucleus?
    the nucleus occupies very little of the atom’s volume and contains most of its mass
23. What type of bond do all of the molecules in the table above have in common?
    covalent
24. When methane (CH4) gas is burned in the presence of oxygen, the following chemical reaction occurs. CH4 + 2 O2 → CO2 + 2 H2O If 1 mole of methane reacts with 2 moles of oxygen, then
    6.02 * 1023 molecules of CO2 and 1.2 * 1024 molecules of H2O are produced.
25. Which of the following ordered pairs of elements shows an increase in atomic number but a decrease in average atomic mass?
    Co to Ni
26. Which of the following is an observable property of many acids?
    they react with metals to release hydrogen gas
27. How many moles of carbon-12 are contained in exactly 6 grams of carbon-12? 0.5 moles
28. Why are enormous amounts of energy required to separate a nucleus into its component protons and neutrons even though the protons in the nucleus repel each other?
    The forces holding the nucleus together are much stronger than the repulsion between the protons.
29. Under what circumstance might a gas decrease in volume when heated?
    The gas is placed under increasing pressure.
30. The random molecular motion of a substance is greatest when the substance is
    a gas
31. Generally, how do atomic masses vary throughout the periodic table of the elements?
    They increase from left to right and top to bottom
32. Why is cobalt (Co) placed before nickel (Ni) on the periodic table of the elements even though it has a higher average atomic mass than nickel?
    Nickel has one more proton
33. In which of the following reactions involving gases would the forward reaction be favored by an increase in pressure?
    A + B ↔ AB
34. Potassium hydroxide (KOH) is a strong base because it
    easily releases hydroxide ions
35. Iodine would have chemical properties most like
    chlorine (Cl)
36. A catalyst can speed up the rate of a given chemical reaction by
    lowering the activation energy required for the reaction to occur
37. The chart above shows the relationship between the first ionization energy and the increase in atomic number.  The letter on the chart for the alkali family of elements is
    W
38. The specific heat of copper is about 0.4 joules/gramºC.  How much heat is needed to change the temperature of a 30 gram sample of copper from 20.0 ºC to 60.0 ºC?
    480 J
39. C3H8 + O2 → CO2 + H2O This chemical equation represents the combustion of propane.  When correctly balanced, the coefficient for water is
    4
40. Which of the following elements has the same Lewis dot structure as silicon?
    germanium (Ge)
41. Which of the following changes will cause an increase in the rate of the above reaction?
    increasing the concentration of Br2
42. Under the same conditions of pressure and temperature, a liquid differs from a gas because the molecules of the liquid
    have stronger forces of attraction between them.
43. How many atoms are in a chromium sample with a mass of 13 grams?
    1.5 * 1023 atoms
44. The reason salt crystals, such as KCl, hold together so well is because the cations are strongly attracted to
    neighboring anions
45. What is the equivalent of 423 kelvin in degrees Celsius?
    150 ºC
46. If the attractive forces among solid particles are less than the attractive forces between the solid and a liquid, the solid will
    dissolve as particles are pulled away from the crystal lattice by the liquid molecules.
47. What information do the experimental results above reveal about the nucleus of the gold atom?
    The nucleus is small and is the densest part of the atom.
48. Standard temperature and pressure (STP) are defined as
    0 C and 1.0 atm pressure
49. Copper(II) nitrate and sodium hydroxide solutions react in a test tube as shown below. Cu(NO3)2 (aq) + 2 NaOH (aq) → Cu(OH)2 (s) + 2 NaNO3 (aq) If nitric acid is added to the test tube, the amount of solid precipitate decreases.  The best explanation for this is that the acid
    will react with the copper(II) hydroxide to form water and soluble copper(II) nitrate.
50. How many moles of CH4 are contained in 96.0 grams of CH4?
    6.00 moles
51. Which reaction diagram shows the effect of using the appropriate catalyst in a chemical reaction?
    D
52. Which element is capable of forming stable, extended chains of atoms through single, double, or triple bonds with itself?
    carbon
53. Which of the substances in the table can act as either the solute or the solvent when mixed with 100 grams of water at 20ºC?
    CH3CH2OH
54. A 2-cm thick piece of cardboard placed over a radiation source would be most effective in protecting against which type of radiation?
    alpha
55. When someone standing at one end of a large room opens a bottle of vinegar, it may take several minutes for a person at the other end to smell it.  Gas molecules at room temperature move at very high velocities, so what is responsible for the delay in detection of the vinegar?
    random collisions between air and vinegar molecules.
56. Which would be most appropriate for collecting data during a neutralization reaction?
    pH probe
57. Proteins are large macromolecules composed of thousands of subunits.  The structure of the protein depends on the sequence of
    amino acids
58. Fe2O3 + 3 CO → 2 Fe + 3 CO2 In this reaction, how many grams of Fe2O3 are required to completely react with 84 grams of CO?
    160 g
59. Which of the following is a balanced equation for the combustion of ethanol (CH3CH2OH)?
    CH3CH2OH + 3O2 → 2CO2 + 3H2O
60. In a sealed bottle that is half full of water, equilibrium will be attained when water molecules
    evaporate and condense at equal rates.
61. How many atoms are contained in 97.6 g of platinum (Pt)?
    3.01 * 1023 atoms
62. 2 CO + O2 → 2 CO2 If the above reaction takes place inside a sealed reaction chamber, then which of these procedures will cause a decrease in the rate of reaction?
    Increasing the volume inside the reaction chamber.
63. How many moles of HNO3 are needed to prepare 5.0 liters of a 2.0 M solution of HNO3?
    10
64. A mass of 5.4 grams of aluminum (Al) reacts with an excess of copper(II) chloride (CuCl2) in solution, as shown below. 3 CuCl2 + 2 Al → 2 AlCl3 + 3 Cu What mass of solid copper (Cu) is produced?
    19 g
65. A scientist observed changes in the gas pressure of one mole of a gas in a sealed chamber with a fixed volume.  To identify the source of the changes, the scientists should check for variations in the
    temperature of the chamber.
66. Which of the examples above illustrates a nonpolar solute in a polar solvent?
    C10H8 in water
67. The above picture shows a light bulb connected to a battery with the circuit interrupted by a solution.  When dissolved in the water to form a 1.0 molar solution, all of the following substances will complete a circuit allowing the bulb to light except
    sucrose
68. If the solubility of NaCl at 25ºC is 36.2 g/100 g H2O, what mass of NaCl can be dissolved in 50.0 g of H2O?
    18.1 g
69. Methane (CH4) gas diffuses through air because the molecules are
    moving randomly.
70. For the polymer, polyvinyl chloride (PVC), ~CH2CH(Cl)CH2CH(Cl)CH2CH(Cl)~ the repeating subunit is
    CH2CH(Cl).
71. Matter is made of atoms that have positive centers of neutrons and protons surrounded by a cloud of negatively charged electrons.  This statement is
    a theory
72. Equal volumes of 1 molar hydrochloric acid (HCl) and 1 molar sodium hydroxide base (NaOH) are mixed.  After mixing, the solution will be
    nearly neutral
73. NH4Cl (s) + heat ↔ NH3 (g) + HCl (g) What kind of change will shift the reaction above to the right to form more products?
    a decrease in total pressure