Liquid Chromatography

9. 1 Orbitals and Theories of Chemical Bonding 1. Which single of the statements concerning valency join (VB) and molecular(a)(a)(a) orbital (MO) follow theories is correct? a) MO possibleness call ins that electrons ar localized between pairs of instalments. b) In VB theory, bind electrons are delocalized over the molecule. c) MO theory accurately describes bonding in O2 and NO, VB theory does not. d) VB theory potentiometer describe molecular bonding in excited states. e) MO theory is used to accurately predict the colors of compounds. react c 9. 2 Valence Bond Theory 2. Which of the neighboring(a) statements is/are proper? . The overlap between an s orbital and a p orbital is called a pi-bond. 2. The overlap of 2 s orbitals in H2 is called a sigma bond. 3. HF is ruleed from the overlap of a total heat 1s orbital with a fluorine 2s orbital. a) 1 only(prenominal)b) 2 onlyc) 3 onlyd) 2 and 3e) 1, 2, and 3 coiffe b 3. Which of the following statements concerning cross orbitals is/are CORRECT? 1. The go of hybrid orbitals equals the number of particleic orbitals that are used to create the hybrids. 2. When moleculeic orbitals are hybridized, the s orbital and at least one p orbital are eer hybridized. 3.To create octahedral buildings, two d orbitals must be hybridized along with the s and all three p orbitals. a) 1 onlyb) 2 onlyc) 3 onlyd) 2 and 3e) 1, 2, and 3 make out e 4. How umteen sigma (? ) bonds and pi (? ) bonds are in ethene, C2H4? a) cardinal ? , one ? b) four ? , two ? c) five ? , one ? d) five ? , two ? e) sise ? , zip ? serve up c 5. How many sigma (? ) bonds and pi (? ) bonds are in carbon monoxide? a) three ? , zero ? b) two ? , one ? c) two ? , two ? d) one ? , two ? e) zero ? , three ? termination d 6. How many sigma (? ) bonds and pi (? ) bonds are in the following molecule? a) seven ? nd three ? b) seven ? and two ? c) five ? and five ? d) five ? and three ? e) five ? and two ? wait on a 7. To form a molecul e with a rhombohedral bipyramidal electron geometry, what set of pure atomic orbitals must be mixed? a) one s and three p b) one s, three p, and one d c) one s, three p, and two d d) two s, six p, and two d e) two s, six p, and four d decide b 8. What is the maximum number of hybridized orbitals formed by a fluorine atom? a) 1b) 2c) 3d) 4e) 6 resolving power d 9. What is the crossway of either carbon atom in acetylene, C2H2? a) spb) sp2c) sp3d) sp3de) sp3d2 make a 10.What is the hybridization of the nitrogen atom in NCl3? a) spb) sp2c) sp3d) sp3de) sp3d2 resolution c 11. What is the hybridization of the xenon atom in XeF2? a) spb) sp2c) sp3d) sp3de) sp3d2 Answer d 12. What is the hybridization of the central nitrogen atom in nitrite ion, NO2-? a) spb) sp2c) sp3d) sp3de) sp3d2 Answer b 13. What is the hybridization of the chlorine atom in chlorite ion, ClO2-? a) spb) sp2c) sp3d) sp3de) sp3d2 Answer c 14. What is the hybridization of the central atom in a molecule with a square-p lanar molecular geometry? a) spb) sp2c) sp3d) sp3de) sp3d2 Answer e 15.What is the hybridization of from each one carbon atom in benzene, C6H6? Benzene contains a six-member carbon ring. a) spb) sp2c) sp3d) sp3de) sp3d2 Answer b 16. For which of the following molecules does the central carbon atom take sp2 hybridization? a) Cl2COb) CHCl3c) CS2d) CH2Cl2e) HCN Answer a 17. For which of the following molecules and ions does the central nitrogen atom feed sp3 hybridization? a) NO2-b) HNO3c) NOBrd) NBr3e) HNO2 Answer d 18. For which of the following molecules and ions does the central atom have sp hybridization NO2+, O3, and I3-? a) NO2+ onlyb) O3 onlyc) I3- onlyd) O3 and I3-e) I3- and NO2+ Answer a 9. What is the molecular geometry just about a central atom that is sp3 hybridized and has two lone pairs of electrons? a) bent b) analogue c) trigonal-planar d) trigonal-pyramidal e) trigonal-bipyramidal Answer a 20. What is the molecular geometry around a central atom that is sp3d2 hybr idized and has one lone pair of electrons? a) tetrahedral b) trigonal-bipyramidal c) square-planar d) square-pyramidal e) see-saw Answer d 21. What is the molecular geometry around a central atom that is sp2 hybridized, has three sigma bonds, and one pi bond? a) trigonal-planar b) trigonal-pyramidal c) bent d) T-shaped e) tetrahedral Answer a 2. What is the molecular geometry around a central atom that is sp3d hybridized and has one lone pair of eletrons? a) trigonal bipyramidal b) trigonal-pyramidal c) see-saw d) tetrahedral e) square-planar Answer c 23. What is the hybridization of a central atom that has four sigma bonds and has no lone pairs of electrons? a) spb) sp2c) sp3d) sp3de) sp3d2 Answer c 24. Upon heating, CaCO3 decomposes to CaO and CO2. What change in the hybridization of carbon occurs in this reaction? a) sp to sp2b) sp2 to sp3c) sp3 to spd) sp2 to spe) no change Answer d 25. One product of the combustion of ethane, C2H6, is carbon dioxide.What change in hybridization of the carbon occurs in this reaction? a) sp3 to sp2b) sp3 to spc) sp2 to sp3d) sp2 to sp3d2e) sp2 to sp Answer b 26. Nitric acid, HNO3, dissociates in water to form nitrate ions and hydronium ions. What change in hybridization of the nitrogen atom occurs in this dissociation? a) sp2 to sp3b) sp2 to spc) sp3 to spd) sp to sp3e) no change Answer e 27. Which of the following hybridized atoms is not possible? a) an sp hybridized carbon atom b) an sp2 hybridized sulfur atom c) an sp3 hybridized phosphorus atom d) an sp3d hybridized oxygen atom e) an sp3d2 hybridized xenon atom Answer d 8. Which of the following characteristics apply to SO2? 1. polar bonds 2. nonpolar molecule 3. linear molecular shape 4. sp hybridized a) 1 onlyb) 1 and 2c) 3 and 4d) 1, 2, and 3e) 1, 2, 3, and 4 Answer a 29. Dichloromethane, CH2Cl2, is a parkland organic solvent. Which of the following statements concerning dichloromethane is/are CORRECT? 1. CH2Cl2 has two isomers. For one isomer of CH2Cl2, the chlorine atoms are adjacent to each other and the molecule is polar. 2. CH2Cl2 has two isomers. For one isomer of CH2Cl2, the chlorine atoms are on opposites sides of the carbon atom and the molecule is nonpolar. 3.The hybridization of the central carbon atom is sp3. a) 1 onlyb) 2 onlyc) 3 onlyd) 1 and 2e) 1, 2, and 3 Answer c 30. For which of the following compounds is it possible for cis and trans isomers to constitute? a) 1 onlyb) 2 onlyc) 3 only d) 1 and 2e) 1, 2, and 3 Answer b 31. Which of the underlined atoms (C1, C2, N, and O) are sp2 hybridized? a) C1 and C2 b) C1, N, and O c) N and O d) O and C2 e) O only Answer a 9. 3 Molecular Orbital Theory 32. All of the following statements concerning molecular orbital (MO) theory are correct EXCEPT a) the Pauli exclusion principle is obeyed. b) Hunds rule is obeyed. ) electrons are depute to orbitals of successively higher verve. d) a bonding molecular orbital is lower in energy than its fire atomic orbitals. e) the combination of two at omic orbitals creates only one molecular orbital. Answer e 33. atomic orbitals combine about effectively to form molecular orbitals when a) electrons in the orbitals have no spins. b) electrons in the orbitals have the same spin. c) the atomic orbitals are hybridized. d) the atomic orbitals have similar energies. e) p-orbitals are half-filled. Answer d 34. A molecular orbital that decreases the electron density between two nuclei is said to be ________. ) hybridizedb) bondingc) antibondingd) pi-bondinge) nonpolar Answer c The following molecular orbital plat may be used for problems 35-48. For oxygen and fluorine, the ? 2p orbital should be lower in energy than the ? 2p. However, the diagram will still yield correct bond order and magnetic behavior for these molecules. Energy ________ ? *2p ________ ________ ? 2p ________ ? 2p ________ ________ ? 2p ________ ? 2s ________ ? 2s ________ ? *1s ________ ? s 35. According to molecular orbital theory, which of the following species is the most belike to exist? a) H22-b) He2c) Li22-d) Be2e) Be22- Answer e 36. According to molecular orbital theory, which of the following species is least likely to exist? a) Be2b) F22+c) C22-d) Li2e) B22- Answer a 37. According to molecular orbital theory, which of the following species has the highest bond order? a) F2b) F22+c) C22-d) Li2e) B22+ Answer c 38. According to molecular orbital theory, what is the bond order of oxygen, O2? a) 1b) 3/2c) 2d) 5/2e) 3 Answer c 39.According to molecular orbital theory, what is the bond order of N2-? a) 1b) 3/2c) 2d) 5/2e) 3 Answer d 40. According to molecular orbital theory, which of the following lists ranks the oxygen species in terms of increasing bond order? a) O22+ O22- O2 b) O22- O2 O22+ c) O2 O22+ O22- d) O2 O22- O22+ e) O22+ O2 O22- Answer b 41. Consider the molecules B2, C2, N2 and O2. Which two molecules have the same bond order? a) B2 and C2b) B2 and O2c) C2 and N2d) C2 and O2e) N2 and O2 Answer d 42. Use molecular orbital theory to predict which species is paramagnetic. ) N2b) O2c) F2d) Li2e) H2 Answer b 43. Use molecular orbital theory to predict which ion is paramagnetic. a) F22+b) O22-c) O22+d) N22+e) B22- Answer a 44. What is the molecular orbital configuration of F2? a) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)2 (? *2p)2 b) core electrons (? 2s)2 (? *2s)2 (? 2p)2 (? 2p)2 (? *2p)2 c) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? *2p)4 d) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)2 (? *2p)6 e) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)2 (? *2p)4 Answer e 45. What is the molecular orbital configuration of N22+? a) core electrons (? s)2 (? *2s)2 (? 2p)4 (? 2p)2 (? *2p)2 b) core electrons (? 2s)2 (? *2s)2 (? 2p)4 c) core electrons (? 2s)2 (? *2s)2 (? 2p)2 (? 2p)2 d) core electrons (? 2s)4 (? *2s)4 e) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)2(? *2p)4 Answer b 46. Assume that the molecular orbital energy diagram for a homonuclear dia tomic molecule applies to a heteronuclear diatomic molecule. What is the molecular orbital configuration of NO? a) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)2 (? *2p)1 b) core electrons (? 2s)2 (? *2s)2 (? 2p)2 (? 2p)2 (? *2p)2 c) core electrons (? 2s)2 (? 2s)2 (? 2p)2 (? 2p)3 d) core electrons (? 2s)2 (? *2s)2 (? 2p)4 (? 2p)1 e) core electrons (? 2s)2 (? *2s)2 (? 2p)2 Answer a 47. Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule, determine which of the following species has the highest bond order. a) NO-b) OF-c) CN-d) O2e) NO Answer c 48. Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule, determine which of the following species is paramagnetic. a) NO+b) COc) CN-d) OF-e) NOAnswer e 49. Which molecule will have the following valence molecular orbital level energy diagram? ? *2p ? *2p ? 2p pic ? 2p pic pi c ? *2s pic ? 2s picpic a) Li2b) Be2c) B2d) C2e) N2 Answer e 50. The following valence molecular orbital energy level diagram is appropriate for which one of the listed species? ? 2p ? *2p pic pic ? 2p pic ? 2p pic pic ? *2s pic ? 2s picpic a) B22-b) C22-c) N22-d) O22-e) F22- Answer c 51. Which molecule will have the following valence molecular orbital energy level diagram? ? *2p ? *2p ? 2p ? 2p pic pic ? *2s pic ? 2s picpic a) Li2b) Be2c) B2d) C2e) F2 Answer d 52. In the NO2- ion, each atom can be viewed as sp2 hybridized. Thus, each atom has one remaining unhybridized p orbital. How many ? 2p molecular orbitals (including both bonding and antibonding orbitals) are formed using the unhybridized p orbitals? a) 1b) 3c) 4d) 6e) 12 Answer b 53. Benzene, C6H6, consists of a six member ring of sp2 hybridized carbon atoms. Each carbon atom has one unhybridized p orbital. How many ? p bonding, antibonding, and nonbonding molecular orbitals exist for benzene? a) Three ? 2p molecular orbitals exist two bonding and one antibonding. b) Three ? 2p molecular orbitals exist one bonding, one antibonding, and one nonbonding. c) Six ? 2p molecular orbitals exist three bonding and three antibonding. d) Six ? 2p molecular orbitals exist two bonding, two nonbonding, and two antibonding. e) twelve ? 2p molecular orbitals exist six bonding and six antibonding. Answer c Short Answer Questions 54. Which theory, valence bond or molecule orbital, correctly predicts the existence of paramagnetic molecules?Answer molecular orbital theory 55. In valence bond theory, each sigma bond in CH4 is formed from the overlap of a hydrogen atoms 1s orbital with a ____ hybridized orbital on the carbon atom. Answer sp3 56. In molecular orbital theory, the bond order is defined as 1/2(the number of electrons in ________ orbitals minus the number of electrons in antibonding orbitals). Answer bonding 57. Triiodide ion, I3-, has a trigonal-bipyramidal electron-p air geometry and a linear molecular geometry. The hybridization of the central iodine atom is ________. Answer sp3d 58. The hybridization of the xenon atom in XeOF4 is ________.Answer sp3d2 59. Draw a Lewis structure of xenon trioxide. What is the hybridization of the xenon atom in this molecule? Answer The hybridization is sp3. 60. Draw the valence molecular orbital energy level diagram for nitrogen monoxide, NO. ? *2p pic ? *2p ? 2p pic ? 2p pic pic ? *2s pic ? 2s picpic Answer pic pic pic pic