When Ag'begins to precipitate, CaSO4(s)Ca2++SO42 z0.14 z2x0.14=Kp(CaS04)=9.1x106z=6.5x103M 4.(5 points) Anwser:(①)Cu2*(aq)+2e=CuS)1)）△，Gn8,=-zFE°=-2Fx0.3394Y Cu'(aq)+e=Cu(s)2) △Gnm91=-zFE29=-1Fx0.5180 1)-2)x2=3yCu2*(aq)+Cu(s)=2Cu(aq)3)△，Gm°3=-RTlnK0 △Gm91-2△Gm2=△，Gme3,-2Fx0.3394+2x1Fx0.5180=-RTlnKO. 2x96485x0.3394+2x96485x0.5180=-8.314x2981n9,Ke=9.1x107 (2) Cu2(aq)+2e =Cu(s)1) △，Gn91=-zFE,°=-2Fx0.3394V Cu(aq)+e==Cu(s)2) △，Gm91=-zFE2°=-1Fx0.5180V Cu*+2Cl=CuCl2"3) △，Gnme3=-RTlnK,9 1)-2x2)+2X3)=4) Cu2"(aq)+Cu(s)+4CT(aq)---2CuClz(aq)4)A.G.=-RTlnK △Gm91-2△，Gnm92+2△Gm93=△Gm°4. -2Fx0.3394+2x1Fx0.5180-2x8.314x298ln6.91x10=-RTlnKO, e=4.34x103 第4页When Ag+ begins to precipitate, CaSO4(s) Ca2+ + SO4 2- z 0.14 z 2 x 0.14 = Ksp(CaSO4) = 9.1 x 10-6 z = 6.5 x 10-5 M 4. (5 points) Anwser: (1) Cu2+(aq)＋2e－ === Cu(s) 1) ΔrGm Θ 1 = -zFE1 = -2F x 0.3394V; Cu+ (aq)＋e － === Cu(s) 2) ΔrGm Θ 1 = -zFE2 = -1F x 0.5180V; ____________________________________ 1) -2) x 2 = 3): Cu2+(aq)＋Cu(s) ===2 Cu+ (aq) 3) ΔrGm Θ 3 = -RTlnKΘ ΔrGm Θ 1 -2ΔrGm Θ 2 =ΔrGm Θ 3, -2F x 0.3394 + 2 x 1F x 0.5180 = -RTlnKΘ, 2 x 96485 x 0.3394 + 2 x 96485 x 0.5180 = -8.314 x 298 ln KΘ, KΘ = 9.1 x 10-7 (2) Cu2+(aq)＋2e－ === Cu(s) 1) ΔrGm Θ 1 = -zFE1 = -2F x 0.3394V; Cu+ (aq)＋e － === Cu(s) 2) ΔrGm Θ 1 = -zFE2 = -1F x 0.5180V; Cu+ + 2Cl- = CuCl2 - 3) ΔrGm Θ 3 = -RTlnKf Θ 1）- 2 x 2) + 2 x 3) = 4): Cu2+(aq)＋Cu(s)＋4Cl- (aq)===2CuCl2 - (aq) 4) ΔrGm Θ 4= -RTlnKΘ ΔrGm Θ 1 -2ΔrGm Θ 2 + 2ΔrGm Θ 3 = ΔrGm Θ 4, -2F x 0.3394 + 2x 1F x 0.5180 – 2 x 8.314 x 298 ln6.91x104 = -RTlnKΘ, KΘ = 4.34 x 103 第 4 页