Bonding Chemistry

(A) A network solid with covalent bonding (B) A molecular solid with zero dipole moment (C) A molecular solid with hydrogen bonding (D) An ionic solid (E) A metallic solid 9. Silicon dioxide, SiO2.

A

(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 12. Is used to explain why the boiling point of HF is greater than the boiling point of HBr

A

31. The structural isomers C2H5OH and CH3OCH3 would be expected to have the same values for which of the following? (Assume ideal behavior.) (A) Gaseous densities at the same temperature and pressure (B) Vapor pressures at the same temperature (C) Boiling points (D) Melting points (E) Heats of vaporization

A

40. The geometry of the SO3 molecule is best described as... (A) trigonal planar (B) trigonal pyramidal (C) square pyramidal (D) bent (E) tetrahedral

A

41. Which of the following molecules has the shortest bond length? (A) N2 (B) O2 (C) Cl2 (D) Br2 (E) I2

A

57. Molecules that have planar configurations include which of the following? I. BCl3 II. CHCl3 III. NCl3 (A) I only (B) III only (C) I and II only (D) II and III only (E) I, II, and III

A

62. The electron-dot structure (Lewis structure) for which of the following molecules would have two unshared pairs of electrons on the central atom? (A) H2S (B) NH3 (C) CH4 (D) HCN (E) CO2

A

68. Which of the following molecules has a dipole moment of zero? (A) C6H6 (benzene) (B) NO (C) SO2 (D) NH3 (E) H2S

A

The boiling points of the elements helium, neon, argon, krypton, and xenon increase in that order. Which of the following statements accounts for this increase? (A) The London (dispersion) forces increase. (B) The hydrogen bonding increases. (C) The dipole-dipole forces increase. (D) The chemical reactivity increases. (E) The number of nearest neighbors increases.

A

(A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 4. The molecule with the largest dipole moment.

B

(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 13. Is used to explain the fact that the four bonds in methane are equivalent

B

28. The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+ II. O2− is more negatively charged than F− III. The O2− ion is smaller than the F− ion (A) II only (B) I and II only (C) I and III only (D) II and III only (E) I, II, and III

B

80. For which of the following molecules are resonance structures necessary to describe the bonding satisfactorily? (A) H2S (B) SO2 (C) CO2 (D) OF2 (E) PF3

B

(A) A network solid with covalent bonding (B) A molecular solid with zero dipole moment (C) A molecular solid with hydrogen bonding (D) An ionic solid (E) A metallic solid 8. Solid ethyl alcohol, C2H5OH

C

(A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 10. Contains 1 sigma (σ) and 2 pi (π) bonds

C

(A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 8. Has the largest bond-dissociation energy

C

47. CCl4, CO2, PCl3, PCl5, SF6 Which of the following does not describe any of the molecules above? (A) Linear (B) Octahedral (C) Square planar (D) Tetrahedral (E) Trigonal pyramidal

C

58. On a mountaintop, it is observed that water boils at 90°C, not at 100°C as at sea level. This phenomenon occurs because on the mountaintop the... (A) equilibrium water vapor pressure is higher due to the higher atmospheric pressure (B) equilibrium water vapor pressure is lower due to the higher atmospheric pressure (C) equilibrium water vapor pressure equals the atmospheric pressure at a lower temperature (D) water molecules have a higher average kinetic energy due to the lower atmospheric pressure (E) water contains a greater concentration of dissolved gas

C

(A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 3. The molecule with only one double bond.

D

(A) Li2 (B) B2 (C) N2 (D) O2 (E) F2 9. Has a bond order of 2

D

(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 14. Is used to explain the fact that the carbon-to-carbon bonds in benzene, C6H6, are identical

D

17. The Lewis dot structure of which of the following molecules shows only one unshared pair of valence electron? (A) Cl2 (B) N2 (C) NH3 (D) CCl4 (E) H2O2

D

32. CH3CH2OH boils at 78 °C and CH3OCH3 boils at − 24 °C, although both compounds have the same composition. This difference in boiling points may be attributed to a difference in... (A) molecular mass (B) density (C) specific heat (D) hydrogen bonding (E) heat of combustion

D

32. Types of hybridization exhibited by the C atoms in propene, CH3CHCH2, include which of the following? I. sp II. sp2 III. sp3 (A) I only (B) III only (C) I and II only (D) II and III only (E) I, II, and III

D

40. Of the following molecules, which has the largest dipole moment? (A) CO (B) CO2 (C) O2 (D) HF (E) F2

D

42. The SbCl5 molecule has trigonal bipyramid structure. Therefore, the hybridization of Sb orbitals should be... (A) sp2 (B) sp3 (C) sp2d (D) sp3d (E) sp3d2

D

66. Ca, V, Co, Zn, As Gaseous atoms of which of the elements above are paramagnetic? (A) Ca and As only (B) Zn and As only (C) Ca, V, and Co only (D) V, Co, and As only (E) V, Co, and Zn only

D

68. In which of the following processes are covalent bonds broken? (A) I2(s) I2(g) (B) CO2(s) CO2(g) (C) NaCl(s) NaCl(l) (D) C(diamond) C(g) (E) Fe(s) Fe(l)

D

According to the VSEPR model, the progressive decrease in the bond angles in the series of molecules CH4, NH3, and H2O is best accounted for by the... (A) increasing strength of the bonds (B) decreasing size of the central atom (C) increasing electronegativity of the central atom (D) increasing number of unshared pairs of electrons (E) decreasing repulsion between hydrogen atoms

D

(A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 5. The molecule that has trigonal pyramidal geometry.

E

(A) hydrogen bonding (B) hybridization (C) ionic bonding (D) resonance (E) van der Waals forces (London dispersion forces) 11. Is used to explain why iodine molecules are held together in the solid state

E

15. In a molecule in which the central atom exhibits sp3d2 hybrid orbitals, the electron pairs are directed toward the corners of... (A) a tetrahedron (B) a square-based pyramid (C) a trigonal bipyramid (D) a square (E) an octahedron

E

18. The liquefied hydrogen halides have the normal boiling points given above. The relatively high boiling point of HF can be correctly explained by which of the following? (A) HF gas is more ideal. (C) HF molecules have a smaller dipole moment. (B) HF is the strongest acid. (D) HF is much less soluble in water. (E) HF molecules tend to form hydrogen bonds.

E

34. X = CH3-CH2-CH2-CH2-CH3 Y = CH3-CH2-CH2-CH2-OH Z = HO-CH2-CH2-CH2-OH Based on concepts of polarity and hydrogen bonding, which of the following sequences correctly lists the compounds above in the order of their increasing solubility in water? (A) Z < Y < X (B) Y < Z < X (C) Y < X < Z (D) X < Z < Y (E) X < Y < Z

E

51. Pi bonding occurs in each of the following species EXCEPT... (A) CO2 (B) C2H4 (C) CN− (D) C6H6 (E) CH4

E

59. Which of the following compounds is ionic and contains both sigma and pi covalent bonds? (A) Fe(OH)3 (B) HClO (C) H2S (D) NO2 (E) NaCN

E

60. Which of the following has a zero dipole moment? (A) HCN (B) NH3 (C) SO2 ( D) NO2 (E) PF5

E

Of the following compounds, which is the most ionic? (A) SiCl4 (B) BrCl (C) PCl3 (D) Cl2O (E) CaCl2

E