Al2O;>AIF3>AICl3.10.HgO+2e+H2O>Hg+20H:Zn-2e+20H>Zn(OH)2 NaO:(-)Zn(s)IZn(OH)2(s)/OH(aq)/HgO(s)/Hg(s)(+). Please balance the following chemical equations(5 equations,2 points for each one,10 points in total) 1. PbCl2+ H20 →Pb(OHCI+HCI B2H6(g)+6HO0) →2HB03+6H2 3. 2 Ni(OH)2+CIO →2 NiO(OH+CI+H0 2 KMnO4+5 H202+3 H2S04>2MnSO4+502+K2S04+8H2O Hg22++ 4I (excess) →Hg+HgL2 Simple questions(two questions,5 points for each one,10 points in total) 1.Anwser:O,as its valence electron shell is 2s22p4 When one e is removed,more energy is required to remove the second ewhen the p orbital is half-filled which is stable in view of energy. 2.Answer:Addition of excess NaOH to the solution of Zn2+,Co2*and Alresults in precipitate of Co(OH)2 and formation of soluble Al(OH)4'and Zn(OH)4 complexes. Separate the precipitate Co(OH)2 by centrifugation from the solution,then add HCI, NH3.H2O,acetone,KSCN subsequently to Co(OH)2.blue color will be observed, indicating the presence of Co2.To the solution of Al(OH)4 and Zn(OH)complexes is added HCI and NH3.H2O,then Al(OH)3 precipitate will form,which is separated and identified by forming red solid after reaction with HAc and Al regeant,the Zn2 is identified by formation of white ZnS after reaction of Zn with NaS. Answer the following questions according to requests(4 questions,20 points in total) 1.(5 points)(1) Anwser:(1)AgCl-Ag+CI' At equilibrium x0.05 第2页Al2O3>AlF3 > AlCl3. 10．HgO+2e + H2O→Hg + 2OH- ； Zn -2e + 2OH- →Zn(OH)2； NaO; (-) Zn(s)|Zn(OH)2(s)|OH- (aq)|HgO(s)|Hg(s) (+). 四、Please balance the following chemical equations (5 equations, 2 points for each one, 10 points in total) 1． PbCl2＋ H2O ⎯⎯→ Pb(OH)Cl + HCl 2． B2H6(g)＋ 6 H2O(l) ⎯⎯→ 2H3BO3 + 6H2 3． 2 Ni(OH)2＋ ClO- ⎯⎯→ 2NiO(OH) + Cl- + H2O 4． 2 KMnO4＋ 5 H2O2＋ 3 H2SO4 ⎯⎯→ 2MnSO4 + 5 O2 + K2SO4 +8H2O 5． Hg2 2+ ＋ 4 I- （excess） ⎯⎯→ Hg + HgI4 2- 五、Simple questions (two questions, 5 points for each one, 10 points in total) 1．Anwser: O, as its valence electron shell is 2s2 2p4 . When one e- is removed, more energy is required to remove the second e- when the p orbital is half-filled which is stable in view of energy. 2. Answer: Addition of excess NaOH to the solution of Zn2+，Co2+ and Al3+ results in precipitate of Co(OH)2 and formation of soluble Al(OH)4 - and Zn(OH)4 - complexes. Separate the precipitate Co(OH)2 by centrifugation from the solution, then add HCl, NH3.H2O, acetone, KSCN subsequently to Co(OH)2, blue color will be observed , indicating the presence of Co2+. To the solution of Al(OH)4 - and Zn(OH)4 - complexes is added HCl and NH3.H2O, then Al(OH)3 precipitate will form, which is separated and identified by forming red solid after reaction with HAc and Al regeant; the Zn2+ is identified by formation of white ZnS after reaction of Zn2+ with Na2S. 六、Answer the following questions according to requests (4 questions, 20 points in total) 1．(5 points) (1) Anwser: (1) AgCl Ag+ + Cl￾At equilibrium x 0.05 第 2 页