Answers to Selected and Numerical Chapter and Unit Review Questions

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1 UNIT 1 Chapter 1 Appendix A Answers to Selected and Numerical Chapter and Unit Review Questions 15. (a) 2-bromopropane (b) cyclopentanol (c) pentanoic acid (d) ethyl propanoate (e) 5-ethyl-5,6-dimethyl-3-heptanone 16. (a) 3,5,7-trimethylcycloheptene (b) 3-ethyl-2-hexanol (c) 1-ethyl-4-methylbenzene (d) 2-methylpentanoic acid (e) N-ethyl-N-methyl-1-butanamine (f) N-butylpropanamide 22. (a) either 2-methylhexanal or pentanal (b) pentane (c) 1,2-dimethylbenzene (d) N-ethyl-N-methylpentanamide (e) 2-methylpropanoic acid butanol, 2-butanol, 2-methyl-1-propanol, 1,1-dimethylethanol, 1-methoxypropane, 1-ethoxyethane, 2-methoxypropane 24. butanoic acid, 2-methylpropanoic acid, methyl propanoate, ethyl ethanoate, 1-propyl methanoate, 2-propyl methanoate (Note: ther isomers are possible that contain hydroxyl and carbonyl groups, or alkoxy and carbonyl groups, but these are beyond the scope of this course.) Chapter (b) 1-bromopropane, 2-bromopropane (c) 2-bromopropane 13. (a) propene 18. (a) 2,3-dibromobutane (b) 1-bromopentane + water (c) propanoic acid (d) propene + water (e) 3-methyl-2-butanone (f) methyl propanoate + water (g) pentane (h) ethanoic acid + ethanol 20. (a) ethene (b) 1-propanol (c) bromine (d) 3-methyl-2-butanone (e) propanoic acid + 1-butanol (f) butanal (g) 2-ethyl-1-butanol, 2-ethylbutanal (h) cyclobutanol (i) 1-butene Unit 1 Review 25. ethanoic acid ethyl-4-methylhexanal, 3-ethyl-4-methylhexanoic acid 28. (a) butanoic acid (b) methanol (c) methyl pentanoate (d) 2-butanone (e) N-methylethanamine (f) 4,5-dimethylheptanal 30. (a) 3-ethyl-4-methyl-1-hexene (b) methoxypropane (c) 3-methyl-1-pentanamine (d) 5-ethyl-3,7,9-trimethyl-2-decanol (e) butyl propanoate 31. (a) 5-methyloctanoic acid (b) N-ethyl-1-butanamine (c) 6-ethyl-5-methyl-2-octyne (d) butanamide (e) 6-ethyl-7-methyl-4-decanone (f) 2-ethyl-3-methylcyclohexanol (g) 4,4,6,6-tetramethylheptanal (h) 4-ethyl-3,5-dimethylcyclopentene (i) N-ethyl-N-methylethanamide (j) 3,6,7-trimethylcyclononanone 32. (a) 4-methyl-2-heptanone (b) 3,3-dimethylhexane (c) 2,5-octanediol 36. (d) propyl methanoate + water (e) 1-heptene + water 37. (b) decanoic acid + 1-propanol 38. (a) ethyne (b) 1-chloro-2-methylpentane (c) heptanoic acid + 1-butanol (d) 2-methylpropanoic acid (e) 3-ethyl-4,4-dimethyl-2-pentanol UNIT 2 Chapter p orbital in third energy level 8. S ground state: 1s 2 2s 2 2p 6 3s 2 3p 4 ; excited: 1s 2 2s 2 2p 6 3s 2 3p 3 4s 1 9. (a) Na, smaller Z eff (b) K, more energy levels (c) Sr, more energy levels (d) Ga more energy levels (e), smaller Z eff (f) Br, more energy levels 10. U, f block, inner transition; Zr, d block, transition; Se, p block, main group; Dy, f block, inner transition; Kr, p block, main group; Rb, s block, main group; Re, d block, transition; Sr, s block, main group 11. Na 2, K 2, Mg, Ca, Al 2 3,Ga 2 3, Si 2, Ge (a) 18 (b) 15 (c) 4 (d) infinite 15. (a) Mg: 1s 2 2s 2 2p 6 3s 2 (b) Cl: 1s 2 2s 2 2p 6 3s 2 3p 5 (c) Mn:1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 5 (d) Y: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d s 2, n = 8, l = (a) Sr has greater n but K has a smaller Z eff (b) both have 4s 2 valence energy level (c) Ca has a greater n but also a greater IE (a) Rb (b) Ti (c) Mg (d) As 23. (a) Al: 1s 2 2s 2 2p 6 3s 2 3p 1 ; Sc: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 1 (b) MR Appendix A

2 Chapter 4 3. (a) C (b) 6. (a) dipole-dipole and dispersion forces (b) ionic bonds (c) metallic bonds (d) dispersion forces 7. Cs, S, Kr, because of large EN difference between atoms and small size of C 3 8 (dispersion forces), C 2 5 (dispersion forces and hydrogen bonding), K (metallic bonding), Si 2 (network solid) 14. all tetrahedral; CCl 4 is non-polar; C 3 Cl and C 2 Cl 2 both polar with dipole-dipole forces. 16. (a) bent (b) octahedral (c) trigonal pyramidal 17. (a) Cl 2 (b) BrCl 19. linear with VSEPR notation AX 2 E 3 (e.g., XeF 2 ) or square planar with notation AX 4 E 2 (e.g., XeF 4 ). 20. non-polar 24. no; 7 pairs of electrons in the valence shell 26. SF 4 : seesaw shape and polar; SiF 4 : tetrahedral shape and non-polar 31. N 2 4 hydrogen bonding, greater dispersion forces (18 electrons) higher boiling point; C 2 4 lower dispersion forces (10 electrons) Unit 2 Review 13. N: 1s 2 2s 2 2p 3 ; P: [Ne]3s 2 3p 3 ; As: [Ar]3d 10 4s 2 4p Mg, Na, Ca, K 15. AX 2 E or AX 2 E 2 Br Br Br 17. (a) Rb < K < Na < Li (b) Li < Be < B < C 29. titanium 30. group 14 (IVA) 31. LiBr 32. (a) As (b) P (c) Be 36. (a) N more electrongative (b) F more electronegative (c) Cl more electronegative 37. (a) Cl Cl < Br Cl < Cl F (b) Si Si < S Cl < P Cl < Si Cl (except for non-polar Cl Cl and Si Si, left atom in each bond pair has partial positive charge, and right atom has partial negative charge) 38. trigonal pyramidal or T-shaped, but not trigonal planar S dipole; 41. tetrahedral; bond dipoles for C shorter than for C Cl 42. neither has expanded valence level; 43. 1s 2 2s 2 2p 6 3p (a) n = 2, l = 0, m l = 0, m s =+ 1 2 (b) n = 3, l = 1, m l = 1, m s = (a) shiny, malleable, conductor of heat and electricity, fairly high melting (or boiling) point (b) form cations by giving up electrons, form basic oxides when dissolved in water 49. (b) K (difference between I.E. 1 and I.E. 2 ); can infer the number of valence electrons because of the size of the I.E. difference) UNIT 3 Cl Chapter 5 8. (a) 60.0 C (b) 50.0 C 9. (a) 2225 kj/mol kj/g; 869 kj/mol kj kj kj 14. (b) 188 kj/mol kj 16. (a) 2657 kj (c) kj (b) kj/mol; 47.5 kj/g 21. (b) 2 kj Chapter 6 F Ba 2+ P F 7. (a) mol/(l s) (b) g 8. (a) k = s 1 ;t 1/2 = 69 s s 11. (b) k = L/(mol s) 12. (a) rate = k[a] 2 [B] (b) third order (c) k = 625 L 2 /(s mol 2 ) 13. (a) rate = k[g 2 Cl 2 ][C ] 2 (b) k = L 2 /(mol 2 s) (c) rate = mol/(l s) F S Cl Appendix A MR 575

3 14. (a) 0.80 (b) (a) 0.20 (b) (a) 12.1 kj/mol Unit 3 Review 27. (a) 47 kj/mol L 30. (b) 82.5 kj kj 38. (b) ~ 6800 kj/mol UNIT 4 Chapter 7 7. decrease in temperature 8. left 10. [ 2 ] = mol/l; [I] = mol/l 11. [S 3 ] = 0.13 mol/l g ethyl propanoate 13. [C] = [ 2 ] = mol/l; [ 2 ] = [C 2 ] = mol/l 14. K c = (a) 2(g) + 4Cl (g) 2 2 (g) + 2Cl 2(g) (b) (a) S 3(g) + 6F (g) SF 6(g) (g) 19. (a) 4N 3(g) + 5 2(g) 4N (g) (g) (b) mol/l; pollution sources 26. left; right; left; no effect; at constant volume, no effect Chapter 8 2. (a) weak acid (b) weak acid (c) weak base (d) weak base 3. (a) 2 + (b) N 4 (c) 2 C 3 2 (d) C 3 4. (a) F (b) T (c) T mol/l Cl 4 < 0.02 mol/l Cl < 0.20 mol/l C 3 C < 2.0 mol/l NaCl 2 6. (a) S 4 (b) S 2 2 (c) P 4 2 (d) C 3 7. (a) S = ; S 3 = (b) S + 2 (l) 2 S (aq) + (aq); S 3 (aq) + 2 (l) 2 S 3(aq) + (c) K b for S = ; K b for S 3 = (d) S 10. (a) number of atoms bonded to central atom; number of (b) Br 3, 2 S 3, Cl 3, Cl mol/l (a) p = 2.10; 0.79% dissociation (b) p = 2.60; 2.5% dissociation (c) p = 3.12; 7.6% dissociation 15. (a) p = 4.36; 0.067% (b) Cl, p = p = K a = Br < Br 2 < Br 3 < Br 4 ; opposite order for conjugate bases < 2 S < C 3 C < Br (b) mol/l; 12:1 Chapter 9 1. (a) N 4 Cl (b) KS 4 (c) NaP 4 (d) Al(N 3 ) 3 7. (a) (N 4 ) 2 S 4 ;N 4 Br; Cu(N 3 ) 2 (b) KS; LiCN; Ca(N 2 ) (a) K sp = [Cu + ][Br ] (b) K sp = [Ca 2+ ][Cr 2 4 ] (c) K sp = [Ni 2+ ][ ] 2 (d) K sp = [Mg 2+ ] 3 [P 3 4 ] 2 (e) K sp = [Mg 2+ ][N + 4 ][P 3 4 ] P 4 (aq) + 2 (l) (aq) + P 4 (aq) 18. NaI since [I ] [Pb 2+ ]:[Ba 2+ ] = 130: mol/l mol/l 25. (a) ml (b) 3.29% (c) steps 1 and AgCl, lower K sp 27. BaS (a) C 3 CAg (s) Ag + (aq) + C 3 C (aq) (b) 23.3 g (c) as Cu reacts, solid dissolves to replace the Ag (a) 41.7 ml (b) 8.86 (c) phenolphthalein Unit 4 Review [N 18. 2(g) ][ 2(g) ] 3 [N 3(g) ] (a) C 3 (aq) + P 4 (aq) C 3 (aq) + 2 P 4 (aq) 2 (b) A 1 = C 3 (aq) B 1 = C 3 (aq) A 2 = 2 P 4 (aq) B 2 = P 4 (aq) (c) reactants since K a for 2 P 4 (aq) > K a for C 3 (aq) [ 3 + (aq)] = mol/l, [ ] = mol/l, p = 2.76, p = MR Appendix A

4 25. 2Ag + (aq) + C 3 2 (aq) Ag 2 C 3(s) mol/l g 29. remove C 2, increase temperature 30. (b) [PCl 5 ] = mol/l. [PCl 3 ] = 0.38 mol/l, [Cl 2 ] = 0.16 mol/l 31. (a) (b) Na (s) Na + (aq) + (aq); N 3(aq) + 2 (l) + N 4 (aq) + (aq); C 3 C (aq) + 2 (l) C 3 C (aq) + (aq); C 3 C (l) + 2 (l) C 3 C (aq) (aq) 33. K sp = [Pb 2+ ][Cl ] 2 = (a) decrease (b) Q c > K c, [N 3 ] decreases mol % 37. (c) [X 2(g) ] = mol/l; [ 2(g) ] = mol/l ppm = mol/l; precipitation occurs 47. (b) 7.74 UNIT 5 Chapter (a) Zn (s) + 2AgN 3(aq) Zn(N 3 ) 2(aq) + 2Ag (s) (b) 3CoBr 2(aq) + 2Al (s) 3Co (s) + 2AlBr 3(aq) (c) Cd (s) + SnCl 2(aq) CdCl 2(aq) + Sn (s) 2. (a) Zn (s) + 2Ag + (aq) + 2N 3 (aq) Zn 2+ (aq) + 2N 3 (aq) + 2Ag (s) Zn (s) + 2Ag + (aq) Zn 2+ (aq) + 2Ag (s) (b) 3Co 2+ (aq) + 6Br (aq) + 2Al (s) 3Co (s) + 2Al 3+ (aq) + 6Br (aq) 3Co 2+ (aq) + 2Al (s) 3Co (s) + 2Al 3+ (aq) (c) Cd (s) + Sn 2+ (aq) + 2Cl (aq) Cd 2+ (aq) + 2Cl (aq) + Sn (s) Cd (s) + Sn 2+ (aq) Cd 2+ (aq) + Sn (s) 3. (a) oxidizing agent: Ag + ; reducing agent: Zn (b) oxidizing agent: Co 2+ ; reducing agent: Al (c) oxidizing agent: Sn 2+ ; reducing agent: Cd 4. (a) oxidation half-reaction: Zn Zn e reduction half-reaction: Ag + + e Ag (b) oxidation half-reaction: Al Al e reduction half-reaction: Co e Co (c) oxidation half-reaction: Cd Cd e reduction half-reaction: Sn e Sn 5. (a) metallic element n-metallic element (c) non-metallic element (d) metallic element 6. (a) Ba =+2; Cl =1 (b) C =+4; S =2 (c) Xe =+4; F =1 7. (a) Ba +2; 1 (f) S 0 (b) Al +3; C 4 (g) As +3; 2 (c) K +1; C +2; N 3 (h) V +5; 2 (d) Li +1; N +3; 2 (i) Xe +6; 2; F 1 (e) N 3; +1; C +3; 2 (j) S +2.5; 2 8. Cl 2 9. (a) yes; oxidizing agent: 2 ; reducing agent: C 6 6 (c) yes; oxidizing agent: I 2 ; reducing agent: 2 (d) yes; oxidizing agent: KMn 4 ; reducing agent: CuCl. 10. (a) yes; Cu undergoes oxidation; Ag + undergoes reduction. (c) yes; Mn 2+ undergoes oxidation; Bi 3 undergoes reduction. 11. (a) +5 in V 2 5,V + 2,V 3,V 3 4,V ; +4 in V 2,V (a) all three steps (b) Step 1: oxidizing agent: 2 ; reducing agent: N 3 Step 2: oxidizing agent: 2 ; reducing agent: N Step 3: oxidizing agent: N 2 ; reducing agent: N (a) I 2 + 2e 2I (b) Pb Pb e (c) AuCl 4 + 3e Au + 4Cl (d) C C 3 C e (e) S e 8 2 S (f) As As e 15. (a) Mn 2 + 2Cl Mn 2+ + Cl (b) 2N + 3Sn N 2 + 3Sn 2+ (c) 3Cd V Cd + 2V (d) 2Cr Cr() (e) S Ni Ni() 2 + 2S 3 2 (f) 2Sn Sn (a) 3SiCl 4 + 4Al 3Si + 4AlCl 3 (b) 4P P (c) I C I 2 + 5C 2 (d) 2S S (a) 2N N 2 + N (b) Cl Cl + Cl (a) 2Co 3+ + Cd 2Co 2+ + Cd 2+ 2Co(N 3 ) 3(aq) + Cd (s) 2Co(N 3 ) 2(aq) + Cd(N 3 ) 2(aq) (b) 2Ag + + S Ag + S AgN 3(aq) + S 2(g) (l) 2Ag (s) + 2 S 4(aq) + 2N 3(aq) (c) Al + Cr Al() 3 + Cr() Al (s) + Na 2 Cr 4(aq) (l) Al() 3(s) + Cr() 3(s) + 2Na (aq) F 2 2F (a) 2P P P 4 (b) reduced Appendix A MR 577

5 23. (a) 2Al + Fe 2 3 2Fe + Al 2 3 (b) yes; oxidizing agent: Fe 2 3 ; reducing agent: Al 24. (a) I N 3 2I N (b) 31.7 g 27. (a) P P 2 + P 3 (c) 2.74 kg 32. (a) C C 2 6 C 2 5 C 3 C (a) Na +1; Al +3; 2; +1; C +4 (b) NaAl() 2 C 3 + 4Cl NaCl + AlCl C (a) 2KCl 3 2KCl S + 2 S 2 (b) oxidizing agent and reducing agent: KCl 3 ; oxidizing agent: 2 ; reducing agent: S 35. N N (b) CaC Ca() 2 + C 2 2 ; not redox (c) 2C C ; redox Chapter Mg (s) Mg 2+ (aq) (1 mol/l) Cd 2+ (aq) (1 mol/l) Cd (s) 3. oxidation: N (g) (l) N 3 (aq) (aq) + 3e reduction: I 2(s) + 2e 2I (aq) overall: 2N (g) (l) + 3I 2(s) 2N 3 (aq) (aq) + 6I (aq) 6. spontaneous: N 2 (g) (aq) + 2Cu (s) + 2I (aq) N 2(g) + 2 (l) + 2CuI (s) E cell = V non-spontaneous: N 2(g) + 2 (l) + 2CuI (s) N 2 (g) (aq) + 2Cu (s) + 2I (aq) E cell =1.955V 7. (a) oxidizing agent: Pb 2 ; reducing agent: Pb (b) oxidizing agent: PbS 4 ; reducing agent: PbS 4 8. Co 3+ (aq),br 2(aq), + (aq), Zn 2+ (aq) 9. Al (s), 2(g),Ag (s),cl (aq) 11. (a) oxidation: Zn (s) Zn 2+ (aq) + 2e reduction: Fe 2+ (aq) + 2e Fe (s) cell potential: V; spontaneous (b) oxidation: Cr (s) Cr 3+ (aq) + 3e reduction: Al 3+ (aq) + 3e Al (s) cell potential: V; non-spontaneous (c) oxidation: 2 2(aq) 2 + (aq) + 2(g) + 2e reduction: Ag + (aq) + e Ag (s) cell potential: V; spontaneous g 14. (a) E cell = V oxidation: Fe (s) Fe 2+ (aq) + 2e reduction: Ag + (aq) + e Ag (s) overall: Fe (s) + 2Ag + (aq) Fe 2+ (aq) + 2Ag (s) (b) E cell =1.247 V oxidation: Ag (s) Ag + (aq) + e reduction: Fe 2+ (aq) + 2e Fe (s) overall: Fe 2+ (aq) + 2Ag (s) 2Ag + (aq) + Fe (s) 17. The cost for Al would be 2.56 times the cost for Na. Unit 5 Review 14. (a) +3 (b) +5 (c) +4 (d) N 3; +1; S +6; no 16. (a) Ca() 2(aq) + C 2(g) CaC 3(s) + 2 (l) 17. (a) g e 2g (b) Ti e Ti (c) I I e 20. (a) 3Fe (s) + 8N 3(aq) 3Fe(N 3 ) 2(aq) + 2N (g) (l) (b) 3Fe(N 3 ) 2(aq) + 4N 3(aq) 3Fe(N 3 ) 3(aq) + N (g) (l) (c) 3Fe (s) + 12N 3(aq) 3Fe(N 3 ) 3(aq) + 3N (g) (l) 21. (b) oxidation: 2I I 2 + 2e reduction: Ag + + e Ag overall: 2I + 2Ag + I 2 + 2Ag (d) V 22. (a) no Cl Cl 4 (b) yes; oxidizing agent: Cl 3 ; reducing agent: I 2 3I 2 + 5Cl I 3 + 5Cl (c) yes; oxidizing agent: Br 2 ; reducing agent: S 2 S 2 + 4Br S Br (d) yes; oxidizing agent: N 3 ; reducing agent: 2 S 2N S 2N + 3S (a) V; non-spontaneous (b) V; spontaneous (c) V; spontaneous 26. (a) 2Mn 4 + 5C Mn C (b) mol/l % 29. (a) 6 (b) (a) C (b) 74.5 h g t 44. (a) 8Al + 3N 4 Cl 4 4Al N 4 Cl oxidizing agent: N 4 Cl 4 ; reducing agent: Al (b) 2 2(l) + 2(l) 2 2 (g) 578 MR Appendix A