Test bank for Chemistry The Central Science 10th Edition by Brown, LeMay, Bursten

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1 Test bank for Chemistry The Central Science 10th Edition by Brown, LeMay, Bursten Chapter 9, Molecular Geometry and Bonding Theories Multiple-Choice and Bimodal 1) For a molecule with the formula A) linear or bent B) linear or trigonal planar C) linear or T-shaped D) T-shaped E) trigonal planar Diff: 1 Page Ref: Sec. 9.1 AB2 the molecular shape is. 2) According to VSEPR theory, if there are five electron domains in the valence shell of an atom, they will be arranged in a(n) geometry. A) octahedral B) linear C) tetrahedral D) trigonal planar E) trigonal bipyramidal Answer: E ) According to VSEPR theory, if there are four electron domains in the valence shell of an atom, they will be arranged in a(n) geometry. A) octahedral B) linear C) tetrahedral D) trigonal planar E) trigonal bipyramidal 4) The electron-domain geometry and molecular geometry of iodine trichloride are and, respectively. A) trigonal bipyramidal, trigonal planar B) tetrahedral, trigonal pyramidal C) trigonal bipyramidal, T-shaped D) octahedral, trigonal planar E) T-shaped, trigonal planar 5) The molecular geometry of is square planar. A) CCl 4 B) XeF4 C) PH D) XeF 2 E) ICl

2 6) The molecular geometry of the H O + ion is. A) linear B) tetrahedral C) bent D) trigonal pyramidal E) octahedral Diff: 2 Page Ref: Sec. 9. 7) The molecular geometry of the CS2 molecule is. A) linear B) bent C) tetrahedral D) trigonal planar E) T-shaped 8) The molecular geometry of the SiH 2 Cl2 molecule is. A) trigonal planar B) tetrahedral C) trigonal pyramidal D) octahedral E) T-shaped 9) The molecular geometry of the A) bent B) trigonal planar C) trigonal pyramidal D) tetrahedral E) T-shaped Diff: 2 Page Ref: Sec ) The molecular geometry of the A) bent B) trigonal planar C) trigonal pyramidal D) tetrahedral E) T-shaped PHCl2 molecule is. CHCl molecule is. 11) The molecular geometry of the SF 2 molecule is. A) linear B) bent C) trigonal planar D) tetrahedral E) octahedral Diff: 2 Page Ref: Sec. 9.2

3 12) The molecular geometry of the PF 2 + ion is. A) octahedral B) tetrahedral C) trigonal pyramidal D) trigonal planar E) trigonal bipyramidal 1) The F B F bond angle in the BF2 A) 90 B) C) 120 D) 180 E) 60 Answer:C - ion is approximately. 14) The Cl Si Cl bond angle in the SiCl 2 F2 molecule is approximately. A) 90 B) C) 120 D) 180 E) 60 15) The F B F bond angle in the BF molecule is. A) 90 B) C) 120 D) 180 E) 60 Diff: 2 Page Ref: Sec ) The O S O bond angle in SO2 is slightly less than. A) 90 B) C) 120 D) 180 E) 60 Answer:C 17) The F N F bond angle in the A) 90 B) C) 120 D) 180 E) 60 Answer:B NF molecule is slightly less than.

4 18) According to valence bond theory, which orbitals on bromine atoms overlap in the formation of the bond in Br2? A) s B) p C) 4s D) 4p E) d Answer D : Diff: 1 Page Ref: Sec ) The electron-domain geometry of a sulfur-centered compound is trigonal bipyramidal. The hybridization of the central nitrogen atom is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d 20) The hybridization of orbitals on the central atom in a molecule is sp. The electron-domain geometry around this central atom is. A) octahedral B) linear C) trigonal planar E) trigonal bipyramidal E) tetrahedral 2. The electron-domain geometry 21) The hybridization of orbitals on the central atom in a molecule is sp about this central atom is. A) octahedral B) linear C) trigonal planar D) trigonal bipyramidal E) tetrahedral 22) The hybridization of the carbon atom in carbon dioxide is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d 5

5 2) The hybridization of the central atom in the XeF4 molecule is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d Answer: E Diff: 2 Page Ref: Sec ) The electron-domain geometry of the AsF6 - atom for bonding are orbitals. A) sp 2 d 2 B) sp C) sp d 2 sp d D) E) sp 2 Diff: 2 Page Ref: Sec. 9.5 ion is octahedral. The hybrid orbitals used by the As 25) In order to produce sp orbital(s) must be mixed. A) one, two B) one, three C) one, one D) two, two E) two, three hybrid orbitals, s atomic orbital(s) and p atomic 26) The angles between sp 2 A) 45 B) 180 C) 90 D) E) 120 Answer:E orbitals are. 27) There are σ and π bonds in the H C C H molecule. A) and 2 B) and 4 C) 4 and D) 2 and E) 5 and 0 Answer:A

6 28) There are σ and π bonds in the A) 4, 2 B) 6, 4 C) 2, 2 D) 2, 6 E) 6, 2 Answer:E HC=C=CH 2 2 molecule. 29) The total number of π bonds in the H C C C C C N molecule is. A) B) 4 C) 6 D) 9 E) 12 AnswerC 0) There is/are σ bond(s) in the molecule below. A) 1 B) 2 C) 12 D) 1 E) 18 Answer:C

7 1) There is/are π bond(s) in the molecule below. A) 0 B) 1 C) 2 D) 4 E) 16 Answer:C 2) There is/are π bond(s) in the molecule below. A) 7 B) 6 C) 2 D) 1 E) 0 Answer:D ) The Lewis structure of carbon monoxide is given below. The hybridizations of the carbon and oxygen atoms in carbon monoxide are and, respectively. : C O : A) sp, sp B) sp 2, sp C) sp, sp 2 D) sp, sp E) sp 2, sp 2 Diff: 2 Page Ref: Sec. 9.6

8 Multiple-Choice 4) The basis of the VSEPR model of molecular bonding is. A) regions of electron density on an atom will organize themselves so as to maximize s-character B) regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap C) atomic orbitals of the bonding atoms must overlap for a bond to form D) electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions E) hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry 5) According to VSEPR theory, if there are three electron domains in the valence shell of an atom, they will be arranged in a(n) geometry. A) octahedral B) linear C) tetrahedral D) trigonal planar E) trigonal bipyramidal Diff: 2 Page Ref: Sec ) In counting the electron domains around the central atom in VSEPR theory, a is not included. A) nonbonding pair of electrons B) single covalent bond C) core level electronpair D) double covalent bond E) triple covalent bond 7) The electron-domain geometry of is tetrahedral. A) CBr4 B) PH C) CCl2BR2 D) XeF4 E) all of the above except XeF4 Answer: E Diff: 2 Page Ref: Sec ) The O C O bond angle in the CO2- ion is approximately. A) 90 B) C) 120 D) 180 E) 60 Answer:C Diff: 2 Page Ref: Sec. 9.2

9 9) The Cl C Cl bond angle in the CCl2O molecule (C is the central atom) is slightly. A) greater than 90 B) less than C) less than 120 D) greater than 120 E) greater than ) Of the following species, will have bond angles of 120. A) PH B) ClF C) NCl D) BCl E) All of these will have bond angles of ) The molecular geometry of the A) trigonal pyramidal B) trigonal planar C) bent D) tetrahedral E) T-shaped Diff: 2 Page Ref: Sec. 9.2 BrO - ion is. 42) The molecular geometry of the left-most carbon atom in the molecule below is. A) trigonal planar B) trigonal bipyramidal C) tetrahedral D) octahedral E) T-shaped

10 4) The molecular geometry of the right-most carbon in the molecule below is. A) trigonal planar B) trigonal bipyramidal C) tetrahedral D) octahedral E) T-shaped 44) The bond angles marked a, b, and c in the molecule below are about,, and, respectively. A) 90, 90, 90 B) 120, 120, 90 C) 120, 120, D) 109.5, 120, E) 109.5, 90,120 Diff: 2 Page Ref: Sec ) The bond angles marked a, b, and c in the molecule below are about,, and, respectively. A) 109.5, 109.5, B) 120, 109.5, 120 C) 109.5, 109.5, 120 D) 90, 180, 90 E) 109.5, 109.5, 90 Diff: 2 Page Ref: Sec. 9.2

11 46) The bond angle marked a in the following molecule is about. A) 90 B) C) 120 D) 180 E) 60 Answer:C 47) The central iodine atom in the ICl 4 - ion has nonbonded electron pairs and bonded electron pairs in its valence shell. A) 2, 2 B), 4 C) 1, D), 2 E) 2, 4 Answer:E 48) The central iodine atom in IF5 electron pairs in its valence shell. A) 1, 5 B) 0, 5 C) 5, 1 D) 4, 1 E) 1, 4 Answer:A has unbonded electron pairs and bonded 49) The central Xe atom in the XeF 4 molecule has unbonded electron pairs and bonded electron pairs in its valence shell. A) 1, 4 B) 2, 4 C) 4, 0 D) 4,1 E) 4, 2 Answer:B

12 50) An electron domain consists of. a) a nonbonding pair of electrons b) a single bond c) a multiple bond A) a only B) b only C) c only D) a, b, and c E) b and c Answer:D 51) According to VSEPR theory, if there are three electron domains on a central atom, they will be arranged such that the angles between the domains are. A) 90 B) 180 C) D) 60 E) 120 Answer:E 52) According to VSEPR theory, if there are four electron domains on a central atom, they will be arranged such that the angles between the domains are. A) 120 B) C) 180 D) 60 E) 90 Answer:B 5) According to VSEPR theory, if there are two electron domains on a central atom, they will be arranged such that the angles between the domains are. A) 60 B) 120 C) D) 180 E) 90 Answer:D 54) The electron-domain geometry and the molecular geometry of a molecule of the general formula ABn are. A) never the same B) always the same C) sometimes the same D) not related E) mirror images of one another

13 55) The electron-domain geometry and the molecular geometry of a molecule of the general formula ABn will always be the same if. A) there are no lone pairs on the central atom B) there is more than one central atom C) n is greater than four D) n is less than four E) the octet rule is obeyed 56) For molecules of the general formula ABn, n can be greater than four. A) for any element A B) only when A is an element from the third period or below the third period C) only when A is boron or beryllium D) only when A is carbon E) only when A is Xe Consider the following species when answering the following questions: (i) PCl (ii) CCl 4 (iii) TeCl 4 (iv) XeF4 (v) SF 6 57) For which of the molecules is the molecular geometry (shape) the same as the VSEPR electron domain arrangement (electron domain geometry)? A) (i) and (ii) B) (i) and (iii) C) (ii) and (v) D) (iv) and (v) E) (v) only Diff: 2 Page Ref: Sec ) Of the molecules below, only is polar. A) SbF5 B) AsH C) I 2 D) SF6 E) CH 4 Diff: 2 Page Ref: Sec ) Of the molecules below, only is nonpolar. A) CO 2 B) H 2 O C) NH D) HCl E) TeCl 2 Diff: 1 Page Ref: Sec. 9.

14 60) Of the molecules below, only is polar. A) CCl4 B) CH4 C) SeF4 D) SiCl 4 E) BF4 Diff: 1 Page Ref: Sec ) Of the molecules below, only is nonpolar. A) BF B) NF C) IF D) PBr E) BrCl Diff: 1 Page Ref: Sec ) Three monosulfur fluorides are observed: SF 2, SF 4, and SF 6. Of these, is/are polar. A) SF 2 only B) SF 2 and SF 4 only C) SF 4 only D) SF 6 only E) SF 2, SF 4, and SF 6 Diff: 2 Page Ref: Sec. 9. 6) The molecular geometry of the A) linear, nonpolar B) linear, polar C) bent, nonpolar D) bent, polar E) trigonal planar,polar BeCl2 molecule is, and this molecule is. Diff: 1 Page Ref: Sec ) The molecular geometry of the PF molecule is, and this molecule is. A) trigonal planar, polar B) trigonal planar, nonpolar C) trigonal pyramidal, polar D) trigonal pyramidal, nonpolar E) tetrahedral,unipolar Diff: 2 Page Ref: Sec. 9.

15 65) Of the following molecules, only is polar. A) BeCl 2 B) BF C) CBr4 D) SiH Cl 2 2 E) Cl2 Diff: 1 Page Ref: Sec ) Of the following molecules, only is polar. A) CCl 4 B) BCl C) NCl D) BeCl 2 E) Cl2 Diff: 1 Page Ref: Sec ) For molecules with only one central atom, how many lone pairs on the central atom guarantees molecular polarity? A) 1 B) 2 C) 1 or 2 D) E) or Answer:A Diff: 1 Page Ref: Sec ) The molecular geometry of the A) trigonal pyramidal, polar B) tetrahedral, nonpolar C) seesaw, nonpolar D) tetrahedral, polar E) seesaw, polar Diff: 1 Page Ref: Sec ) The molecular geometry of the A) trigonal pyramidal, polar B) trigonal pyramidal, nonpolar C) trigonal planar, polar D) trigonal planar, nonpolar E) trigonal bipyramidal, polar CHF molecule is, and the molecule is. BCl molecule is, and this molecule is. Diff: 1 Page Ref: Sec. 9.

16 70) According to valence bond theory, which orbitals overlap in the formation of the bond in HBr? A) 1s on H and 4p on Br B) 1s on H and 4s on Br C) 1s on H and p on Br D) 2s on H and 4p on Br E) 2s on H and p on Br Diff: 1 Page Ref: Sec ) The combination of two atomic orbitals results in the formation of molecular orbitals. A) 1 B) 2 C) D) 4 E) 0 Answer:B 72) The electron-domain geometry of a carbon-centered compound is tetrahedral. The hybridization of the central carbon atom is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d Diff: 2 Page Ref: Sec ) Of the following, only has A) PH 2- B) CO C) ICl D) I - E) PF5 sp 2 hybridization of the central atom. 74) Of the following, the central atom is A) PCl 5 B) XeF 4 C) PH D) Br - E) BeF 2 d 2 sp hybridized only in.

17 75) The sp d 2 atomic hybrid orbital set accommodates electron domains. A) 2 B) C) 4 D) 5 E) 6 Answer:E 76) The sp 2 atomic hybrid orbital set accommodates electron domains. A) 2 B) C) 4 D) 5 E) 6 Answer:B 77) The hybridizations of nitrogen in NF and NH are and, respectively. A) sp 2, sp 2 B) sp, sp C) sp, sp D) sp, sp E) sp2, sp 78) The hybridizations of iodine in A) sp, spd 2 B) sp d, sp d C) sp d, sp 2 D) sp d, sp d 2, 2 E) sp d sp d IF and IF5 are and, respectively. 79) The hybridizations of bromine in respectively. A) sp, spd 2 B) sp d, sp d C) sp d, sp 2 D) sp d, sp d 2 2 E) sp d, sp d BrF 5 and of arsenic in AsF5 are and,

18 80) The hybrid orbitals used for bonding by the sulfur atom in the A) sp B) sp2 C) sp D) sp d 2 E) sp d 81) The hybrid orbitals used for bonding by Xe in the unstable A) sp 2 B) sp C) sp d 2 D) sp d E) sp Answer:C Diff: 2 Page Ref: Sec. 9.5 SF4 molecule are orbitals. XeF2 molecule are orbitals. 82) The hybridization of the oxygen atom labeled y in the structure below is. The C O H bond angle is. A) sp, 180 B) sp 2, C) sp, D) sp d, 90 E) sp, 90 Answer:C Diff: 2 Page Ref: Sec ) The electron-domain geometry of the AsF 5 molecule is trigonal bipyramidal. The hybrid orbitals used by the As atom for bonding are orbitals. A) sp 2 d 2 B) sp C) sp d 2 D) sp d E) sp 2

19 84) hybrid orbitals are used for bonding by Xe in the A) sp 2 B) sp C) sp d D) sp d 2 E) sp Answer:D XeF4 molecule. Consider the following species when answering the following questions: (i) PCl (ii) CCl 4 (iii) TeCl 4 (iv) XeF4 (v) SF6 85) In which of the molecules does the central atom utilize d orbitals to form hybrid orbitals? A) (i) and (ii) B) (iii) only C) (i) and (v) D) (iii), (iv), and (v) E) (v) only Diff: 2 Page Ref: Sec ) Which of the molecules has a see-saw shape? A) (i) B) (ii) C) (iii) D) (iv) E) (v) Diff: Page Ref: Sec. 9., ) In which of the molecules is the central atom A) (i) and (ii) B) (iii) only C) (iii) and (iv) D) (iv) and (v) E) (v) only Answer:D 2 sp d hybridized? 88) There are unhybridized p atomic orbitals in an sp-hybridized carbon atom. A) 0 B) 1 C) 2 D) E) 4 AnswerC

20 89) When three atomic orbitals are mixed to form hybrid orbitals, how many hybrid orbitals are formed? A) one B) six C) three D) four E) five Answer:C 90) The blending of one s atomic orbital and two p atomic orbitals produces. A) three sp hybrid orbitals B) two sp 2 hybrid orbitals C) three sp hybrid orbitals D) two sp hybrid orbitals E) three sp 2 hybrid orbitals Answer: E 91) A triatomic molecule cannot be linear if the hybridization of the central atoms is. A) sp B) sp 2 C) sp D) sp 2 or sp E) sp 2 d or sp Answer:D d 2 92) A typical double bond. A) is stronger and shorter than a single bond B) consists of one σ bond and one π bond C) imparts rigidity to a molecule D) consists of two shared electron pairs E) All of the above answers are correct. Answer: E 9) A typical triple bond. A) consists of one σ bond and two π bonds B) consists of three shared electrons C) consists of two σ bonds and one π bond D) consists of six shared electron pairs E) is longer than a single bond

21 94) In a polyatomic molecule, "localized" bonding electrons are associated with. A) one particular atom B) two particular atoms C) all of the atoms in the molecule D) all of the π bonds in the molecule E) two or more σ bonds in the molecule 95) Which of the following molecules or ions will exhibit delocalized bonding? SO 2 SO SO2- A) SO2, SO, and SO2- B) SO 2- only C) SO2 and SO D) SO and SO2- E) None of the above will exhibit delocalizedbonding. 96) Which of the following molecules or ions will exhibit delocalized bonding? NO 2 - NO 4 + N - A) NO 4 + and N - B) NO2 - only C) NO2 -, NO 4 +, and N - D) N - only E) NO2 - and N - 97) In order to exhibit delocalized π bonding, a molecule must have. A) at least two π bonds B) at least two resonance structures C) at least three σ bonds D) at least four atoms E) trigonal planar electron domain geometry 98) In a typical multiple bond, the σ bond results from overlap of orbitals and the π bond(s) result from overlap of orbitals. A) hybrid, atomic B) hybrid, hybrid C) atomic, hybrid D) hybrid, hybrid or atomic D) hybrid or atomic, hybrid or atomic

22 99) The carbon-carbon σ bond in ethylene, CH CH, results from the overlap of. 2 2 A) sp hybrid orbitals B) sp hybrid orbitals C) sp2 hybrid orbitals D) s atomic orbitals E) p atomic orbitals 100) The π bond in ethylene, CH CH 2 2, results from the overlap of. A) sp hybrid orbitals B) s atomic orbitals C) sp hybrid orbitals D) sp2 hybrid orbitals E) p atomicorbitals Answer: E 101) In order for rotation to occur about a double bond,. A) the σ bond must be broken B) the π bond must be broken C) the bonding must be delocalized D) the bonding must be localized F) the σ and π bonds must both be broken 102) A typical triple bond consists of. A) three sigma bonds B) three pi bonds C) one sigma and two pi bonds D) two sigma and one pi bond E) three ionic bonds 10) The N N bond in HNNH consists of. A) one σ bond and one π bond B) one σ bond and two π bonds C) two σ bonds and one π bond D) two σ bonds and two π bonds E) one σ bond and no π bonds

23 104) The hybridization of the terminal carbons in the A) sp B) sp2 C) sp D) sp d 2 E) sp d Diff: 2 Page Ref: Sec. 9.6 H C=C=CH 2 2 molecule is. 105) The hybridization of nitrogen in the H C N: molecule is. A) sp B) s 2 p C) s p D) sp2 E) sp 106) The hybridization of the carbon atom labeled x in the molecule below is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d

24 107) The hybridization of the oxygen atom labeled x in the structure below is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d 108) The Lewis structure of carbon dioxide is given below. The hybridization of the carbon atom in carbon dioxide is. A) sp B) sp 2 C) sp D) sp 2 d E) sp 2 d 2 Diff: 2 Page Ref: Sec ) Electrons in bonds remain localized between two atoms. Electrons in bonds can become delocalized between more than two atoms. A) pi, sigma B) sigma, pi C) pi, pi D) sigma, sigma E) ionic, sigma Diff: 2 Page Ref: Sec ) Valence bond theory does not address the issue of. A) excited states of molecules B) molecular shape C) covalent bonding D) hybridization E) multiple bonds Diff: 2 Page Ref: Sec. 9.5

25 111) Structural changes around a double bond in the portion of the rhodopsin molecule trigger the chemical reactions that result in vision. A) protein B) opsin C) retinal D) cones E) rods Answer:C Diff: Page Ref: Sec ) The bond order of any molecule containing equal numbers of bonding and antibonding electrons is. A) 0 B) 1 C) 2 D) E) 1/2 Answer:A Diff: Page Ref: Sec ) In molecular orbital theory, the the H2 molecule. A) filled, filled B) filled, empty C) filled, half-filled D) half-filled, filled E) empty, filled Diff: 4 Page Ref: Sec. 9.7 σ1s orbital is and the σ1s* orbital is in 114) Based on molecular orbital theory, the only molecule in the list below that has unpaired electrons is. A) C2 B) N2 C) F2 D) O2 E) Li2 Diff: Page Ref: Sec ) Based on molecular orbital theory, there are unpaired electrons in the OF+ A) 0 B) C) 1 D) 2 E) 1/2 AnswerD ion. Diff: Page Ref: Sec ) Based on molecular orbital theory, the bond orders of the H H bonds in H 2, H 2 +, and, respectively A) 1, 0, and 0 B) 1, 1/2, and 0 H 2 - are

26 C) 1, 0, and 1/2 D) 1, 1/2, and 1/2 E) 1, 2, and 0 Diff: 4 Page Ref: Sec ) Based on molecular orbital theory, the bond order of the H H bond in the A) 0 B) 1/2 C) 1 D) /2 E) 2 Answer:B Diff: 4 Page Ref: Sec. 9.7 H 2 + ion is. 118) Based on molecular orbital theory, the bond order of the N N bond in the. A) 0 B) 1 C) 2 D) E) 5 Answer:D Diff: 4 Page Ref: Sec. 9.8 N2 molecule is 119) Based on molecular orbital theory, the bond order of the N N bond in the A) 0 B) C) 1 D) 2 E) 1/2 Answer:D Diff: 4 Page Ref: Sec. 9.8 N2 2+ ion is. 120) Based on molecular orbital theory, the bond order of the Be Be bond in the Be2 molecule is. A) 0 B) 1 C) 2 D) E) 4 Answer:A Diff: 4 Page Ref: Sec ) Based on molecular orbital theory, the bond order of the C C bond in the C 2 molecule is. A) 0 B) 1 C) 2 D) E) 4 Answer:C Diff: 4 Page Ref: Sec. 9.8

27 122) An antibonding π orbital contains a maximum of electrons. A) 1 B) 2 C) 4 D) 6 E) 8 Answer:B Diff: Page Ref: Sec ) According to MO theory, overlap of two s atomic orbitals produces. A) one bonding molecular orbital and one hybrid orbital B) two bonding molecular orbitals C) two bonding molecular orbitals and two antibonding molecular orbitals D) two bonding molecular orbitals and one antibonding molecular orbital E) one bonding molecular orbital and one antibonding molecular orbital Answer: E Diff: Page Ref: Sec ) A molecular orbital can accommodate a maximum of electron(s). A) one B) two C) four D) six E) twelve Answer:B Diff: Page Ref: Sec ) Molecular Orbital theory correctly predicts paramagnetism of oxygen gas, O2. A) the bond order in O2 can be shown to be equal to 2. B) there are more electrons in the bonding orbitals than in the antibonding orbitals. C) the energy of the π 2pMOs is higher than that of the σ 2pMO. This is because D) there are two unpaired electrons in the MO electron configuration of O 2 E) the O O bond distance is relatively short Diff: 4 Page Ref: Sec. 9.7, ) Molecular Orbital theory correctly predicts diamagnetism of fluorine gas, F 2. This is because. A) the bond order in F 2 can be shown to be equal to 1. B) there are more electrons in the bonding orbitals than in the antibonding orbitals. C) all electrons in the MO electron configuration of F 2 are paired. D) the energy of the π 2pMOs is higher than that of the σ 2pMO E) the F F bond enthalpy is verylow Diff: 4 Page Ref: Sec. 9.7, 9.8

28 127) Of the following, only appears to gain mass in a magnetic field. A) C2 B) N2 C) F2 D) O2 E) Li2 Diff: 4 Page Ref: Sec ) Of the following, appear(s) to gain mass in a magnetic field. A) O2 B) N2 C) B2 D) N2 B 2 N2 O2 only only and N2 and O2 E) B2 and O2 Answer: E Diff: 4 Page Ref: Sec ) According to MO theory, overlap of two p atomic orbitals produces. A) two bonding molecular orbitals B) one bonding molecular orbital and one antibonding molecular orbital C) two bonding molecular orbitals and two antibonding molecular orbitals D) two bonding molecular orbitals and one antibonding molecular orbital E) three bonding molecular orbitals and three antibonding molecular orbitals Diff: Page Ref: Sec ) According to MO theory, overlap of two p atomic orbitals produces. A) one π MO and one σ* MO B) one π MO and one σ MO C) one π MO and one π* MO or one σ MO and one σ* MO D) one π + MO and one σ* MO D) two π MOs, two π + MOs, one σ MO, and one σ* MO Diff: Page Ref: Sec ) An antibonding MO the corresponding bonding MO. A) is always lower in energy than B) can accommodate more electrons than C) can accommodate fewer electrons than D) is always higher in energy than E) is always degenerate with Diff: Page Ref: Sec. 9.8

29 12) The more effectively two atomic orbitals overlap,. A) the more bonding MOs will be produced by the combination B) the higher will be the energy of the resulting bonding MO and the lower will be the energy of the resulting antibonding MO C) the higher will be the energies of both bonding and antibonding MOs that result D) the fewer antibonding MOs will be produced by the combination E) the lower will be the energy of the resulting bonding MO and the higher will be the energy of the resulting antibonding MO Answer: E Diff: 4 Page Ref: Sec ) The bond order of a homonuclear diatomic molecule can be decreased by. A) removing electrons from a bonding MO or adding electrons to an antibonding MO B) adding electrons to a bonding MO or removing electrons from an antibonding MO C) adding electrons to any MO D) removing electrons from any MO E) The bond order of a homonuclear diatomic molecule cannot be decreased by any means. Diff: 4 Page Ref: Sec ) The order of MO energies in B2, C2, and N2 (σ2p > π2p ) in, is different from the order O2, F2, and Ne2 (σ2p < π2p ) This is due to. A) less effective overlap of p orbitals in O2, F2, and Ne2 B) the more metallic character of boron, carbon and nitrogen as compared to oxygen, fluorine, and neon C) greater 2s-2p interaction in O2, F2, and Ne2 D) greater 2s-2p interaction in B2, C2, and N2 E) less effective overlap of p orbitals in B2, Diff: 5 Page Ref: Sec. 9.8 Short Answer C 2, and N2 1) The 1s hydrogen orbital overlaps with the iodine orbital in HI. Answer: 5p Diff: 2 Page Ref: Sec 9.5 2) A covalent bond in which overlap regions lie above and below an internuclear axis is called a(n). Answer: π bond Diff: 2 Page Ref: Sec 9.6 ) The sensation of vision results from a nerve impulse that is triggered by the separation of retinal from. Answer: opsin Diff: 2 Page Ref: Sec 9.6 4) In molecular orbital theory the stability of a covalent body is related to its. Answer: bond order Diff: 2 Page Ref: Sec 9.7 5) Each molecular orbital can accommodate, at most, two electrons with their spins paired. This is called the. Answer: Pauli principle Diff: 4 Page Ref: Sec 9.8

30 6) The more unpaired electrons in a species, the stronger is the force of magnetic attraction. This is called. Answer: paramagnetism Diff: 1 Page Ref: Sec 9.8 True/False 1) Possible shapes of AB Answer: FALSE Diff: 2 Page Ref: Sec 9.1 molecules are linear, trigonal planar, and T-shaped. 2) Boron trifluoride has three bonding domains and its electron domain geometry is trigonal planar. Answer: TRUE Diff: 2 Page Ref: Sec 9.2 ) Electron domains for single bonds exert greater force on adjacent domains than the electron domains for multiple bonds. Answer: FALSE Diff: 1 Page Ref: Sec 9.2 4) The quantitative amount of charge separation in a diatomic molecule contributes t o the dipole moment of that molecule. Answer: TRUE Diff: 1 Page Ref: Sec 9. 5) Hybridization is the process of mixing atomic orbitals as atoms approach each other to form a bond. Answer: TRUE Diff: 1 Page Ref: Sec 9.5 6) Electrons in core orbitals contribute to atom bonding. Answer: FALSE Diff: 1 Page Ref: Sec 9.6 Algorithmic Questions 1) Using the VSEPR model, the electron-domain geometry of the central atom in BF is. A) linear B) trigonal planar C) tetrahedral D) trigonal bipyramidal E) octahedral 2) Using the VSEPR model, the electron-domain geometry of the central atom in SF2 is. A) linear B) trigonal planar C) tetrahedral D) trigonal bipyramidal E) octahedral

31 ) Using the VSEPR model, the electron-domain geometry of the central atom in ClF is. A) linear B) trigonal planar C) tetrahedral D) trigonal bipyramidal E) octahedral 4) Using the VSEPR model, the electron-domain geometry of the central atom in BrF4 - is. A) linear B) trigonal planar C) tetrahedral D) trigonal bipyramidal E) octahedral Answer: E 5) Using the VSEPR model, the molecular geometry of the central atom in XeF2 is. A) linear B) trigonal planar C) tetrahedral D) bent E) trigonal pyramidal 6) Using the VSEPR model, the molecular geometry of the central atom in BCl is. A) linear B) trigonal planar C) tetrahedral D) bent E) trigonal pyramidal 7) Using the VSEPR model, the molecular geometry of the central atom in CF4 is. A) linear B) trigonal planar C) tetrahedral D) bent E) trigonal pyramidal 8) Using the VSEPR model, the molecular geometry of the central atom in SO2 is. A) linear B) trigonal planar C) tetrahedral D) bent E) trigonal pyramidal 2

32 9) Using the VSEPR model, the molecular geometry of the central atom in NCl is. A) linear B) trigonal planar C) tetrahedral D) bent E) trigonalpyramidal Answer: E 10) Using the VSEPR model, the molecular geometry of the central atom in PF5 is. A) tetrahedral B) square planar C) trigonal bipyramidal D) seesaw E) square pyramidal 11) The hybrid orbital set used by the central atom in NO - is. A) sp B) sp2 C) sp D) sp d 2 E) sp d 12) The hybrid orbital set used by the central atom in BF4 - is. A) sp B) sp2 C) sp D) sp d 2 E) sp d 1) The hybrid orbital set used by the central atom in KrF2 is. A) sp B) sp 2 C) sp D) sp d 2 E) sp d