I- 12-1 11 11.1 2Mg(s) + O 2 (g) 2MgO(s) [Mg 2+ O 2 ] Zn(s) + Cu 2+ (aq) Zn 2+ (aq) + Cu(s) - 2Mg(s) 2Mg 2+ (s) + 4e +) O 2 (g) + 4e 2O 2 (s) 2Mg(s) + O 2 (g) 2MgO(s) Zn(s) Zn 2+ (aq) + 2e +) Cu 2+ (aq) + 2e Cu(s) Zn(s) + Cu 2+ (aq) Zn 2+ (aq) + Cu(s) 12-2 11.2 (1) (2) (3) (4) (i) (ii) F: 1 H:+1 O: 2 3 (5) (4) KH (K:+1, H: 1) CaH 2 (Ca:+2, H: 1) Na 2 O 2 (Na:+1, O: 1) H 2 O 2 (H:+1, O: 1) N: NO 2 (+4), NO (+2), N 2 (0), NH 3 ( 3) C: CCl 4 (+4), CO (+2), HCHO (0), CH 3 OH ( 2), CH 4 ( 4) 1
12-3 (c) χ - 4.1 H 2.20 Li 0.98 Be 1.57 B 2.04 C 2.55 N 3.04 O 3.44 F 3.98 Na 0.93 Mg 1.31 Al 1.61 Si 1.90 P 2.19 S 2.58 Cl 3.16 K 0.82 Ca 1.00 Ga 1.81 Ge 2.01 As 2.18 Se 2.55 Br 2.96 Rb 0.82 St 0.95 In 1.78 Sn 1.96 Sb 2.05 Te 2.10 I 2.66 12-4 p.158 2
12-5 11.3 ΔE φ(cu) φ(zn) = Δφ = ΔE [Cu 2+ ] = [Zn 2+ ] = 1 mol dm 3 at 25 o C, ΔE = 1.10 V Cu 2+ - Zn 2+ Zn 11.4 [H 3 O + ] = 1 mol dm 3 101 kpa 2H 3 O 2+ (1 mol dm 3 ) + 2e H 2 (g, 101 kpa) + H 2 O(l) 12-6 25 o C E o = 0 V 0.76 V i.e., H 3 O + Zn 2+ Zn 2+ + 2e Zn E o = 0.76 V 3
H 2 0 V 1 mol dm 3 φ (A) A 12-7 (1)Zn φ(zn) φ(h 2 ) = Δφ = ΔE = E o (Zn) E o (H 2 ) = E o (Zn) = 0.76 V < 0 Zn Zn2+ (1 mol dm 3 ) + 2e Zn(s) : E o = 0.76 V ΔE o 0 2H 3 O 2+ (1 mol dm 3 ) + 2e H 2 (g, 101 kpa) + H 2 O(l) ) Zn 2+ (1 mol dm 3 ) + 2e Zn(s) : E o = 0.76 V Zn(s) + 2H 3 O 2+ (aq) Zn 2+ (aq) + H 2 (g) + H 2 O(l) : E o = 0 V : ΔE o = 0 ( 0.76) = 0.76 V (2)Cu φ(cu) φ(h 2 ) = Δφ = ΔE = E o (Cu) E o (H 2 ) = E o (Cu) = 0.342 V > 0 Cu Cu 2+ (1 mol dm 3 ) + 2e Cu(s) : E o = 0.342 V ΔE o 0 Cu 2+ (1 mol dm 3 ) + 2e Cu(s) : E o = 0.342 V ) 2H 3 O 2+ (1 mol dm 3 ) + 2e H 2 (g, 101 kpa) + H 2 O(l) : E o = 0 V Cu 2+ + H 2 (g) + H 2 O(l) Cu(s) + 2H 3 O 2+ (aq) : ΔE o = 0.342 0 = 0.342 V E o 1 mol dm 3 101 kpa 12-8 11.1 at 25 o C E o K + (aq) K(s) F 2 (g) F (aq) 4
12-9 (1) (2) (3) (4) (4) 11.2 ( ) Zn(s) Zn 2+ (aq) Cu 2+ (aq) Cu(s) (+) 11.3 (+) Pt(s) H 2 (g) H + (aq) Zn 2+ (aq) Zn(s) ( ) ( ) Pt(s) H 2 (g) H + (aq) Cu 2+ (aq) Cu(s) (+) 12-10 11.5 ( ) Zn(s) Zn 2+ (aq) Ag + (aq) Ag(s) (+) 2 [Ag + (aq) + e Ag(s)] E o = 0.80 V ) Zn 2+ (aq) + 2e Zn(s) E o = 0.76 V Zn(s) + 2Ag + (aq) Zn 2+ (aq) + 2Ag(s) ΔE o = 0.80 ( 0.76) = 1.56 V 1 mol 2 mol 0.80 2 ( 0.76) = 2.36 V 5
dg dw 12-11 ξ ξ + dξ p.135 dg = (ΔG)dξ dg = (ΔG)dξ ΔG < 0 Zn(s) + 2Ag + (aq) Zn 2+ (aq) + 2Ag(s) ΔΕ dξ dw dg ξ Zn(s) + 2Ag + (aq) Zn 2+ (aq) + 2Ag(s) dg = dw (> 0) : dg = (ΔG)dξ, dw = (nfδe)dξ ξ (n = 2) ΔG = nfδe J mol -1 ξ ΔG = nfδe J mol 1 n F C mol 1 ΔE V C V = J : aa + bb + qq + rr + o ξ G X = G X + RT ln[x], 12-12 ΔG = ( qgq + rg R ) ( ag A + bg B ) ΔG = ΔG o + RT ln [Q]q [R] r [A] a [B] b ΔE = ΔE o RT nf ln [Q]q [R] r [A] a [B] b ΔG = nfδe ΔG o = nfδe o at 25 o C ΔE = ΔE o 0.0591 log [Q]q [R] r n [A] a [B] b (Unit:V) Zn(s) + 2Ag + (aq) Zn 2+ (aq) + 2Ag(s) (n = 2) ΔE = ΔE o RT nf ln [Zn2+ ] [Ag + ] 2 = ΔEo RT 2F ln [Zn2+ ] [Ag + ] 2 ξ 6
12-13 dg = (ΔG)dξ < 0 ΔG< 0 G G = n X (ξ) G X (ξ), n X (ξ) = n o X + ν X ξ ΔG ΔE ΔG = 0 GdG = (ΔG)dξ = 0 (ΔG = 0) p.132 9.1 ΔE = 0 V K c ΔG = nfδe ΔG = 0, ΔE = 0, ΔG o = RT ln K c ΔE o = ΔGo nf = RT nf ln K c K c = exp nfδeo RT at 25 o C, ΔE = 0 = ΔE o 0.0591 log K c n K c = 10 nδeo /0.0591 12 K c ΔE o = RT nf ln K c at 25 o C, K c = 10 nδeo /0.0591 (III) Fe 3+ I - 2 [Fe 3+ (aq) + e Fe 2+ (aq)] E o = 0.771 V ) I 3 (aq) + 2e 3I (aq) E o = 0.536 V 2Fe 3+ (aq) + 3I (aq) 2Fe 2+ (aq) + I 3 (aq) ΔE o = 0.235 V 12-14 2Fe 3+ (aq) + 3I (aq) 2Fe 2+ (aq) + I 3 (aq) (n = 2) at 25 o C: K c = 10 nδeo /0.0591 K c = [Fe2+ ] 2 [I 3 ] [Fe 3+ ] 2 [I ] 3 = 102 0.235/0.0591 = 9 10 7 7
12-15 11.6 2 ΔE o ( ) Ag(s) Ag + (0.001 mol dm 3 ) Ag + (1 mol dm 3 ) Ag(s) (+) Ag + (1 mol dm 3, [Ag + ] 1 ) Ag + (0.001 mol dm 3, [Ag + ] 2 ) (n = 1) T 25 o C ΔE = ΔE o RT nf ln [Ag+ ] 2 [Ag + ] 1 = 0 RT F ΔE = 0 0.0591 log 0.001 1 = 0.177 V [Ag + ] ln 2 [Ag + ] 1 12-16 AgCl K sp = [Ag + ][Cl ] = 1.77 10 10 Ag + Ag + [Cl ] = 1 mol dm 3 [Ag + ] = 1.77 10 10 mol dm 3 Ag + (1 mol dm 3 ) Ag + (1.77 10 10 mol dm 3 ) 1.77 10 10 ΔE = 0 0.0591 log = 0.576 V 1 8