Q&A Hero

Q: If figure (1) represents the vapor pressure of water, at 25C, which figure represents the vapor pressure of mercury at 25C? A) figure (2) B) figure (3) C) figure (4)

Q: If figure (1) represents the vapor pressure of diethyl ether, CH3CH2OCH2CH3, at 25C, which figure represents the vapor pressure of ethanol at 25C? A) figure (2) B) figure (3) C) figure (4)

Q: If figure (1) represents the vapor pressure of water at 25C, which figure represents the vapor pressure of ethanol, CH3CH2OH at 25C? A) figure (2) B) figure (3) C) figure (4)

Q: If figure (1) represents the vapor pressure of water at 25C in a 1 liter container, which figure represents the vapor pressure of water at 25C in a 2 liter container? A) figure (2) B) figure (3) C) figure (4)

Q: If figure (1) represents the vapor pressure of water at 25C, which figure represents the vapor pressure of water at 45C? A) figure (2) B) figure (3) C) figure (4)

Q: Which drawing best represents hydrogen bonding in methylamine, CH3NH2? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing below best represents hydrogen bonding methanol, CH3OH? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing best represents hydrogen bonding? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which best indicates the direction of the dipole moment in acetone, (CH3)2C=O? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which best indicates the direction of the dipole moment in formaldehyde, H2C=O? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing best shows the direction of the dipole moment in H2C=CCl2? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing best shows the molecular polarity of methylamine, CH3NH2, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing best accounts for the polarity of methanol, CH3OH, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: Which drawing best accounts for the polarity of water, H2O, and the bond polarities that make a major contribution to the overall molecular polarity? A) drawing (1) B) drawing (2) C) drawing (3) D) drawing (4)

Q: In the drawing of acetic acid, CH3CO2H, a partial negative charge (-) occurs onA) only atom (a).B) only atom (b).C) atoms (a) and (c).D) atoms (b) and (d).

Q: In the drawing of acetic acid, CH3CO2H, a partial positive charge (+) occurs onA) only atom (a).B) only atom (b).C) atoms (a) and (c).D) atoms (b) and (d).

Q: In the drawing of acetaldehyde, CH3CHO, the largest partial negative charge (-) occurs onA) atom (a).B) atom (b).C) atom (c).D) atom (d).

Q: In the drawing of acetaldehyde, CH3CHO, the largest partial positive charge (+) occurs onA) atom (a).B) atom (b).C) atom (c).D) atom (d).

Q: The liquid crystal state A) is a liquid in which the molecules tend to assume an overall orientation with respect to each other. B) occurs when a supercritical fluid is rapidly cooled below the critical point. C) occurs when an amorphous solid first begins to melt. D) occurs when the first crystals form in the liquid during freezing.

Q: A supercritical fluid refers to a substance A) above both its critical temperature and its critical pressure. B) at its triple point. C) that is in the liquid crystal state. D) with a viscosity of zero.

Q: Which transition could occur if a solid is heated at a pressure above the triple point pressure? A) condensation B) deposition C) melting D) sublimation

Q: Which transition could occur if a solid is heated at a pressure below the triple point pressure? A) condensation B) deposition C) melting D) sublimation

Q: The critical temperature of a substance is the A) highest temperature at which the liquid phase can exist in equilibrium with the gas phase. B) temperature above which the compound decomposes. C) temperature at which all three phases can exist in equilibrium. D) temperature at which sublimation occurs.

Q: Pencil lead is actually A) fullerene. B) graphite. C) lead. D) silica.

Q: Diamond is held together by A) covalent bonds. B) dipole-dipole forces. C) London dispersion forces. D) All of these

Q: The layers of graphite are held together by A) covalent bonds. B) dipole-dipole forces. C) London dispersion forces. D) All of these

Q: Which of the following is not an allotrope of carbon? A) coal B) diamond C) fullerene D) graphite

Q: O2 and O3 are ________ of oxygen. A) allotropes B) isomers C) isotopes D) stereomers

Q: A binary ionic compound, MxAy, crystallizes in a cubic structure that contains eight anions (A) entirely within its unit cell and a cation (M) on each corner and on each face. What is the empirical formula of this compound? A) MA B) MA2 C) M2A D) M4A8

Q: How many Cl- ions are around each K+ ion in KCl, which has a cubic unit cell with Cl- ions on each corner and each face? A) 1 B) 4 C) 6 D) 8

Q: The edge length of a face-centered cubic lattice of NaCl is 564 pm. What is the density of NaCl in g/cm3? A) 0.720 B) 1.08 C) 2.16 D) 4.32

Q: An ionic compound crystallizes in a unit cell having a face-centered cubic array of metal ions, Mn+, and all of the tetrahedral holes occupied by anions, X-. The empirical formula of this ionic compound isA) MX.B) MX2.C) M2X.D) M7X4.

Q: An ionic compound crystallizes in a unit cell having a face-centered cubic array of anions, X-, and half of the tetrahedral holes filled with metal ions, Mn+ The empirical formula of this ionic compound isA) MX.B) MX2.C) M2X.D) M2X7.

Q: KCl crystallizes in a cubic unit cell with Cl- ions on each corner and each face. How many K+ ions and Cl- ions are in each unit cell of KCl? A) 1 K+ ion and 1 Cl- ion B) 2 K+ ions and 2 Cl- ions C) 4 K+ ions and 4 Cl- ions D) 8 K+ ions and 8 Cl- ions

Q: The highest coordination number for spherical packing is found in the A) body-centered cubic structure. B) simple cubic structure. C) body-centered cubic and face-centered cubic. D) cubic closest-packing and hexagonal closest packing.

Q: Cubic closest-packing A) has a body-centered cubic unit cell. B) has a face-centered cubic unit cell. C) has a simple cubic unit cell. D) has the same unit cell as hexagonal closest-packing.

Q: Manganese crystallizes in a body-centered cubic structure. What is the coordination number of each atom? A) 4 B) 6 C) 8 D) 12

Q: Cesium has a radius of 272 pm and crystallizes in a face-centered cubic unit cell. What is the edge length of the unit cell? A) 314 pm B) 385 pm C) 544 pm D) 769 pm

Q: An element forms a body-centered cubic crystalline substance. The edge length of the unit cell is 287 pm and the density of the crystal is 7.92 g/cm3. Calculate the atomic weight of the substance. A) 45.0 amu B) 48.0 amu C) 56.4 amu D) 63.5 amu

Q: Silver crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if the atomic radius of silver is 144 pm? A) 204 pm B) 288 pm C) 333 pm D) 407 pm

Q: Rhodium has a face-centered cubic structure and has a density of 12.4 g/cm3. What is its atomic radius? A) 134 pm B) 268 pm C) 380 pm D) 1070 pm

Q: What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 175 pm? A) 247 pm B) 495 pm C) 700 pm D) 1400 pm

Q: Iron crystallizes in a body-centered cubic cell having an edge length of 287 pm. What is the density of iron in g/cm3. A) 1.99 B) 7.85 C) 11.9 D) 15.9

Q: Which type of spherical packing has the most unused space? A) body-centered cubic B) cubic closest-packed C) cubic closest-packed and hexagonal closest-packed D) simple cubic

Q: How many unit cells share an atom that is on the face of a face-centered cubic unit cell? A) 1 B) 2 C) 4 D) 8

Q: When cubic unit cells stack together, how many unit cells share a common corner? A) 2 B) 4 C) 6 D) 8

Q: How many atoms are in one body-centered cubic unit cell of a metal? A) 1 B) 2 C) 3 D) 4

Q: How many atoms are in one face-centered cubic unit cell of a metal? A) 1 B) 2 C) 3 D) 4

Q: The structure of a solid can be determined by diffraction of radiation in which region of the electromagnetic radiation spectrum? A) infrared B) microwave C) visible D) X-ray

Q: The wavelength of light used to observe an object must be ________ than the object itself. A) larger B) smaller C) of higher energy D) of lower energy

Q: Which type of bonding does Mg form upon solidification? A) covalent network B) ionic C) metallic D) molecular

Q: Which of the following compounds forms a covalent network solid? A) C8H18 B) NO2 C) SiO2 D) SnCl4

Q: Which of the following compounds forms a covalent network solid? A) Li B) C (diamond) C) O2 D) CO2

Q: A crystalline solid of unknown origin forms an aqueous solution that conducts an electrical current. The solid has a high melting point and shatters when struck with a hammer. The solid is likely to be A) a covalent network solid. B) an ionic solid. C) a metallic solid. D) a molecular solid.

Q: Which of the following forms an ionic solid? A) Ag B) C7H15NH2 C) RbI D) SO3

Q: Which of the following statements is not consistent with the properties of a molecular solid? A) a compound that conducts electricity when molten B) a low melting solid C) a solid formed by the combination of two nonmetallic elements D) a solid that is a nonconductor of electricity

Q: Which of the following forms a molecular solid? A) CaO B) C10H22 C) C(graphite) D) gold

Q: Which is classified as an amorphous solid? A) palladium(II) chloride B) phosphorus tetrachloride C) plastic D) platinum

Q: Solids having no ordered long-range structure are classified as A) amorphous B) crystalline C) metallic D) molecular

Q: The vapor pressure of liquid chloroform, CHCl3, is 400.0 torr at 24.1C and 100.0 torr at -6.3C. What is Hvap of chloroform?A) 15.3 kJ/molB) 30.1 kJ/molC) 57.6 kJ/molD) 86.7 kJ/mol

Q: Hydroquinone is an antioxidant that is also used as a photographic reducer and developer. The normal boiling point of hydroquinone is 310C. Calculate the pressure at which hydroquinone will boil at 200C given that its Hvap is 73.38 kJ/mol.A) 1.210 10-4 mm HgB) 1.35 mm HgC) 22.5 mm HgD) 757 mm Hg

Q: While mercury is very useful in barometers, mercury vapor is toxic. Given that mercury has a Hvap of 59.11 kJ/mol and its normal boiling point is 356.7C, calculate the vapor pressure in mm Hg at room temperature, 25C.A) 2.68 10-3 mm HgB) 2.99 mm HgC) 372 mm HgD) 753 mm Hg

Q: A kitchen pressure cooker operates at 1.50 atm. The Hvap of water is 40.7 kJ/mol. What is the boiling point of water in the pressure cooker?A) 362 KB) 373 KC) 385 KD) 410 K

Q: The normal boiling point for HBr is higher than the normal boiling point for HCl. This can be explained by A) larger dipole-dipole forces for HBr. B) larger dispersion forces for HBr. C) larger hydrogen-bond forces for HBr. D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for HBr.

Q: Arrange the following in order of increasing boiling point. CH3CH2OH CH3CH2CH3 H3C-O-CH3 CH3CH2NH2 I II III IV A) IV < III < II < I B) II < III < IV < I C) I < IV < III < II D) II < III < I < IV

Q: Which of the following compounds has the highest boiling point? A) CH3CH2OH B) HOCH2CH2OH C) H3C-O-CH3 D) CH3CH2CH2CH3

Q: Which of the following substances has the highest boiling point? A) CH3-CH2-CH2-CH2-CH3 B) Xe C) CH3-CH2-CH3 D) (CH3)4C

Q: Which of the following compounds has the highest boiling point? A) H2O B) HCl C) H2S D) NH3

Q: The normal boiling point occurs when the A) intermolecular forces within the liquid phase are broken. B) temperature of the pure liquid equals the external temperature. C) vapor pressure of a pure liquid equals an external pressure of one atmosphere. D) vapor pressure of the liquid equals the external pressure.

Q: The vapor pressure of a pure liquid increases as the A) average kinetic energy of the molecules in the liquid phase decreases. B) intermolecular attractive forces increase. C) temperature of the liquid phase decreases. D) temperature of the liquid phase increases.

Q: Molecules of a liquid can pass into the vapor phase only if the A) liquid has little surface tension. B) molecules have sufficient kinetic energy to overcome the intermolecular forces in the liquid. C) temperature of the liquid is near its boiling point. D) vapor pressure of the liquid is high.

Q: As a liquid evaporates at a temperature below its boiling point, the temperature of the liquid A) decreases. B) decreases at low temperatures, but increases at high temperatures. C) increases. D) remains unchanged.

Q: When a liquid is heated at its boiling point, the A) covalent bonds are broken, allowing vaporization to occur. B) temperature of the liquid increases. C) temperature of the liquid remains the same as long as any liquid is present. D) temperature of the vapor phase increases.

Q: For the process: HNO3(g) HNO3(l)H is -39.04 kJ/mol and S is -111.74 J/(mol K). What is the normal boiling point of pure HNO3?A) 2.86CB) 76.2CC) 270.3CD) 349.4C

Q: How much heat is released when 75.0 g of steam at 100.0C is cooled to ice at -15.0C? The enthalpy of vaporization of water is 40.67 kJ/mol, the enthalpy of fusion for water is 6.01 kJ/mol, the molar heat capacity of liquid water is 75.4 J/(mol C), and the molar heat capacity of ice is 36.4 J/(mol C).A) 54.8 kJB) 195 kJC) 228 kJD) 248 kJ

Q: CFC-11 (trichlorofluoromethane, CCl3F) has been used for many years as the working fluid in refrigerators. Given its heat of vaporization is 26.88 kJ/mol and its entropy of vaporization is 90.51 J/(mol K), what is the boiling point of CFC-11?A) -272.9CB) 0.297CC) 2.44CD) 23.8C

Q: Bromine is one of only two elements that is a liquid at room temperature. Bromine has a heat of vaporization of 30.91 kJ/mol and its boiling point is 59C. What is the entropy of vaporization for bromine?A) -301 J/(mol K)B) -93.1 J/(mol K)C) 10.7 J/(mol K)D) 93.1 J/(mol K)

Q: Ethyl chloride, C2H5Cl, is used as a local anesthetic. It works by cooling tissue as it vaporizes. The heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 10.0 g of ethyl chloride? A) 4.09 kJ B) 170 kJ C) 264 kJ D) 1700 kJ

Q: When a substance melts at its normal melting point, the sign of H is ________ and the sign of S of this phase change is ________.A) +, -B) -, +C) +, +D) -, -

Q: For which of the following phase changes is the sign of S negative?A) boiling of waterB) formation of snow from water vapor in cloudsC) melting of ice creamD) sublimation of I2