Q&A Hero

Q: Which covalent bond is the most polar?A) N FB) C FC) Cl FD) F F

Q: The bonds in the polyatomic ion CO32- are classified asA) ionicB) metallicC) nonpolar covalentD) polar covalent

Q: A compound having A ions on each corner and B ions on each face of a cubic unit cell has the empirical formula ________.

Q: Ni has a face-centered unit cell. The number of Ni atoms in the unit cell is ________.

Q: A certain metal can exist in two different cubic cells, body-centered cubic and face-centered cubic. Which unit cell will have the greater density?

Q: The cubic unit cell in which the radius of an atom is 31/2 d/4, where d is the unit cell edge length, is the ________ unit cell.

Q: The coordination number of each atom in a simple cubic unit cell is ________.

Q: The two most efficiently packed unit cells have the hexagonal closest-packed and the ________ the atomic arrangements.

Q: The cubic closest-packed arrangement of atoms is the same as which cubic unit cell?

Q: Layers of atoms having a spacing of 105 pm will diffract X-rays with d = 154.2 pm at an angle of ________ degrees.

Q: First-order diffraction of X-rays with d = 154.2 pm at an angle of 32.5 is caused by layers of atoms in a crystalline solid with a spacing of ________ pm.

Q: A low-melting crystalline compound that does not conduct electricity in the solid or liquid state is classified as a ________ solid.

Q: Rubber is classified as an ________ solid, whereas diamond is classified as a ________ solid.

Q: The solids formed by K, K2O2, SiO2, and O2 are classified as ________, ________, ________, and ________, respectively.

Q: Of C2H5OH and C3H5(OH)3 the one expected to have the higher vapor pressure is ________, and the one expected to have the higher boiling point is ________.

Q: The phase change H2(g) ->H2(s) is called ________, and the enthalpy change, H, for this phase change has a ________ sign.

Q: Of C2H5OH and C3H5(OH)3 the one expected to have the higher viscosity is ________, and the one expected to have the higher surface tension is ________.

Q: The property of a liquid that is a measure of the liquid's resistance to increase its surface area is ________.

Q: Helium can be liquefied when He atoms are attracted to one another by intermolecular ________ forces.

Q: The intermolecular forces responsible for CH3CH2OH being at liquid at 20C are ________ bonds.

Q: The intermolecular forces formed when NaCl is dissolved in water are ________ forces.

Q: Pt(NH3)2Cl2 is square planar. The isomer of Pt(NH3)2Cl2 that has a non-zero dipole moment has a Cl-Pt-Cl bond angle of ________ degrees.

Q: The HBr bond has a length of 141 pm and 12.1% ionic character. What is the dipole moment of HBr?

Q: The Br-Cl bond has 5.05% ionic character and a dipole moment of 0.518 D. What is the distance between atoms in BrCl?

Q: LiH has an experimental dipole moment, = 6.00 D. If LiH were 100% ionic, the distance between positive and negative charges would be 161 pm. What is the percent ionic character in the LiH bond?

Q: In the molecule BF3 there is a + charge on the ________ atom and a - charge on the ________ atom.

Q: The bonds in the polyatomic ion NO3- are classified as ________.

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

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

Q: Lithium 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 body-centered cubic structure. What is the edge length of the unit cell? A) 314 pm B) 385 pm C) 544 pm D) 628 pm

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

Q: Nickel has a face-centered cubic structure and has a density of 8.90 g/cm3. What is its atomic radius? A) 125 pm B) 249 pm C) 353 pm D) 997 pm

Q: What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 128 pm? A) 181 pm B) 362 pm C) 512 pm D) 1020 pm

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

Q: Which of the following forms a molecular solid? A) NH4NO3 B) C6H4Cl2 C) SiO2 D) copper

Q: How much heat is released when 105 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) 273 kJC) 319 kJD) 347 kJ

Q: Ethyl chloride, C2H5Cl, is used as a local anesthetic. It works by cooling tissue as it vaporizes; its heat of vaporization is 26.4 kJ/mol. How much heat could be removed by 20.0 g of ethyl chloride? A) 8.18 kJ B) 341 kJ C) 528 kJ D) 3410 kJ

Q: The normal boiling point for H2Te is higher than the normal boiling point for H2Se. This can be explained by A) larger dipole-dipole forces for H2Te. B) larger dispersion forces for H2Te. C) larger hydrogen-bond forces for H2Te. D) larger dipole-dipole forces, larger dispersion forces, and larger hydrogen-bond forces for H2Te.

Q: Which of the following compounds exhibits only dispersion and dipole-dipole intermolecular interactions? A) H2 B) HI C) CO2 D) CH3NH2

Q: In liquid propanol, CH3CH2CH2OH,which intermolecular forces are present? A) Dispersion, hydrogen bonding and dipole-dipole forces are present. B) Only dipole-dipole and ion-dipole forces are present. C) Only dispersion and dipole-dipole forces are present. D) Only hydrogen bonding forces are present.

Q: Which of the following compounds exhibits hydrogen bonding? A) CH3Cl B) HI C) CH3OCH3 D) NH3

Q: Which is expected to have the largest dispersion forces? A) C3H8 B) C12H26 C) F2 D) BeCl2

Q: Which has the smallest dipole-dipole forces? A) CH3Cl B) HBr C) O2 D) NO

Q: Which of the following molecules does not have a dipole moment? A) C2H2 B) H2O C) CH3CH2OH D) H I

Q: Which of the following should have the largest dipole moment? A) F2(g) B) BCl3(g) C) KBr(g) D) CH3I(g)

Q: Which covalent bond is the most polar? A) N- F B) C- F C) Cl- F D) F- F

Q: What is the physical phase of the substance at T = 400 K and P = 2.0 atm? A) gas B) liquid C) solid D) supercritical fluid

Q: What is the physical phase of the substance at T = 225 K and P = 1.1 atm? A) gas B) liquid C) solid D) supercritical fluid

Q: What is the physical phase of the substance at T = 100 K and P = 0.1 atm? A) gas B) liquid C) solid D) supercritical fluid

Q: The approximate normal melting point of this substance is A) 100 K. B) 190 K. C) 300 K. D) 430 K.

Q: The approximate normal boiling point of this substance is A) 180 K. B) 190 K. C) 300 K. D) 430 K.

Q: What phase changes occur when the pressure is held constant at 0.25 atm and the temperature increases from 100C to 300C?A) liquid -> gasB) solid -> gasC) solid -> liquidD) solid -> liquid -> gas

Q: What phase changes occur when the temperature is held constant at 140C and the pressure is increased from 0.25 atm to 1.4 atm?A) gas -> liquid -> solidB) gas -> solid -> liquidC) liquid -> solid -> gasD) solid -> liquid ->vapor

Q: What phases can be present at 200C and 0.75 atm pressure? A) only the vapor phase B) only the liquid phase C) only the solid phase D) both the solid and vapor phases

Q: The normal boiling point of this substance is approximately A) 25C. B) 140C. C) 300C. D) 350C.

Q: From the phase diagram above, the minimum pressure at which this substance can exist in the liquid phase is A) 0.25 atm. B) 0.45 atm. C) 1.0 atm. D) 1.2 atm.

Q: The temperature and pressure at which all three phases can coexist in equilibrium is A) 0.25 atm and 110C. B) 1.0 atm and 140C. C) 1.25 atm and 300C. D) 0.45 atm and 130C.

Q: The solid and liquid phases can exist in equilibrium along line A) AC. B) CB. C) CD. D) BD.

Q: Melting occurs along the A) AC line. B) CB line. C) CD line. D) All of these

Q: According to the diagram, the solid phase of this substance A) has the same density as the liquid phase. B) is less dense than water. C) is less dense than the liquid phase. D) is more dense than the liquid phase.

Q: Consider a compound that undergoes sublimation at 125C and a pressure of one atm. Which of the following could be a heating curve appropriate for heating the compound from 100C to 150C? A) graph a B) graph b C) graph c D) graph d

Q: If cation M has a 2+ charge and anion A has a 2- charge, what is the oxidation state of cation M'? A) +1 B) +2 C) +3 D) +4

Q: What is the empirical formula of the mineral? A) MM'A B) MM'A3 C) M2M'A3 D) M8M'A6

Q: How many anions are in the unit cell? A) 1 B) 2 C) 3 D) 6

Q: How many cations M are in the unit cell? A) 1 B) 2 C) 4 D) 8

Q: A certain mineral crystallizes in the cubic unit cell shown below. M represents the cations and A represents the anions. What is the empirical formula of the mineral? A) MA B) MA2 C) M2A D) M4A4

Q: How many cations and how many anions are in the unit cell? A) 4 cations and 4 anions B) 4 cations and 8 anions C) 4 cations and 14 anions D) 8 cations and 4 anions

Q: What kind of packing do the anions adopt? A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic

Q: Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic

Q: Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic

Q: Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic

Q: Identify the packing in the figure shown below. A) body-centered cubic B) cubic closest packed (face-centered cubic) C) hexagonal closest packed D) simple cubic

Q: What is the formula of the compound formed from M and X? A) MX B) MX2 C) MX3 D) MX4

Q: Which of the areas designated A, B, and C are smallest repeating units, analogous to two-dimensional unit cells? A) only A B) only B C) only C D) A, B, or C

Q: From the plot of vapor pressure as a function of temperature shown below, the normal boiling point for tert-butyl alcohol is approximately A) 0C. B) 40C. C) 85C. D) 100C.

Q: Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for water? A) curve (a) B) curve (b) C) curve (c) D) curve (d)

Q: Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for mercury? A) curve (a) B) curve (b) C) curve (c) D) curve (d)

Q: Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for ethanol? A) curve (a) B) curve (b) C) curve (c) D) curve (d)

Q: Based on the relative strengths of the intermolecular forces of attraction of each substance, which is the most likely vapor pressure vs. temperature curve for diethyl ether? A) curve (a) B) curve (b) C) curve (c) D) curve (d)