全国高中生化学竞赛初赛分类试题库：全套解析答案VIP免费

一、氧化还原反应（A）1.(1)–2/x、+6、+2、–2、+5/2、0、+6、+6、+1/2(2)+2、+7、+2、+6、0、–1(3)+5、+3、+1、–3、+3、+5、0、+5、–22.(1)3Fe3C+40HNO39Fe(NO3)3+13NO+3CO2+20H2O(2)2CrI3+21Cl2+52KOH2K2CrO4+6KIO3+42KCl+26H2O(3)2MoS2+9O2+12NaOH2Na2MoO4+4Na2SO4+6H2O(4)P4+3NaOH+3H2O3NaH2PO2+PH3(5)6HCNS+11KClO36CO2+6NO+6SO2+11KCl+3H2O(6)5+8KMnO4+12H2SO45+5+8MnSO4+4K2SO4+17H2O(7)15Pb(N3)2+44Cr(MnO4)222Cr2O3+44MnO2+90NO+5Pb3O4(8)13P4+10P2I4+128H2O40PH4I+32H3PO43.(1)4PH4+–12e–P4+16H+×1Cr2O72–+14H++6e2Cr3++7H2O×24PH4++2Cr2O72–+12H+P4+4Cr3++14H2O(2)ClO–+H2O+2eCl–+2OH–×2Fe(OH)2+6OH––4eFeO42–+4H2O×12ClO–+Fe(OH)2+2OH–2Cl–+FeO42–+2H2O(3)CuO+H2O+2eCu+2OH–×32NH3+6OH––6eN2+6H2O×13CuO+2NH33Cu+N2+3H2O(4)Zn–2eZn2+×1CNS–+3H++2eH2S+HCN×1Zn+CNS–+3H+Zn2++H2S+HCN(5)CN–+3OH––2eCO32–+NH3×2O2+2H2O+4e4OH–×12CN–+O2+2OH–+2H2O2CO32–+2NH3(6)Al+4OH––3eAl(OH)4–×8NO3–+6H2O+8eNH3+9OH–×38Al+3NO3–+5OH–+18H2O8Al(OH)4–+3NH3(7)Cu3P+4H2O–11e3Cu2++H3PO4+5H+×6Cr2O72–+14H++6e2Cr3++7H2O×116Cu3P+11Cr2O72–+124H+18Cu2++6H3PO4+22Cr3++53H2O(8)Fe+4OH––2eFeO22–+2H2O×3NO2–+5H2O+6eNH3+7OH–×13Fe+NO2–+5OH–3FeO22–+NH3+H2O(9)Cr(OH)4–+4OH––3e2CrO42–+4H2O×2H2O2+2e2OH–×32Cr(OH)4–+3H2O2+2OH–2CrO42–+8H2O(10)N2H4+4OH––4eN2+4H2O×1Cu(OH)2+2eCu+2OH–×2N2H4+2Cu(OH)2N2+Cu+4H2O(11)MnO4–+8H++5eMn2++4H2O×2H2C2O4–2e2CO2+2H+×52MnO4–+5H2C2O4+6H+2Mn2++10CO2+8H2O(12)Cr(NCS)64–+54H2O–97eCr3++6NO3–+6CO2+6SO42–+108H+×1Ce4++eCe3+×97Cr(NCS)64–+97Ce4++54H2O电解Cr3++Ce3++6NO3–+6CO2+6SO42–+108H+(13)Zn+4OH––2eZn(OH)42–×4NO3–+6H2O+8eNH3+9OH–×14Zn+NO3–+6H2O+7OH–4Zn(OH)42–+NH3(14)PbO2+4H++2ePb2++2H2O×5Mn2++4H2O+5eMnO4–+8H+×25PbO2+2Mn2++4H+5Pb2++2H2O+2MnO4–(15)CrO42–+8H++3eCr3++4H2O×8S2O32–+5H2O–8e2SO42–+10H+×38CrO42–+3S2O32–+34H+8Cr3++6SO42–+17H2O4.(1)①2FeS2(s)+7O2+2H2O2Fe2++4SO42–+4H+②FeS2(s)Fe2+(aq)+S22–(aq)③4Fe2++O2+4H+4Fe3++2H2O④14Fe3++FeS2(s)+8H2O15Fe2++2SO42–+16H+⑤Fe3++3H2OFe(OH)3+3H+(2)用Fe(SO4)3溶液洗去煤中的FeS2，则Fe3+变成Fe2+，向洗涤液中通入空气，如上述②反应，Fe2+又变成Fe3+，然后浓缩，又可以用来洗涤煤中的FeS2。5.(1)2MoS2+9O2+12OH–2MoO42–+4SO42–+6H2O(2)MoS2+6HNO3H2MoO4+6NO+2H2SO46NO+9/2O2+3H2O6HNO3MoS2+9/2O2+3H2OH2MoO4+2H2SO46.①Fe+8OH––6eFeO42–+4H2O②6H2O+6e3H2+6OH–③Fe+2H2O+2OH–FeO42–+3H2↑④0.1mol⑤降低。电解煮沸7.(1)2Na+2NaOH(l)Na2O+NaH(2)K+KNO3(l)K2O+N2(3)4CeO2+6H2SO42Ce2(SO4)3+6H2O+O2(4)2NH4Hg2NH3+H2+2Hg8.(1)4Mn(OH)2+O24MnO(OH)+2H2O(2)2MnO(OH)+2I–+6H+2Mn2++I2+4H2O(3)I2+2S2O32–2I–+S4O62–9.(1)6S2Cl2+16NH312NH4Cl+S4N4+S8(2)不能用N2与S反应合成S4N4，由于N2的原子化能大，要实现N2+SN4S4，必须高温，而在高温时N4S4又不能存在，所以直接用惰性的N2合成N4S4不可行。10.S+O2SO22SO2+O22SO3SO3+H2OH2SO4ABCDH2SO4+KOHKHSO42KHSO4K2S2O8+H2EFS+H2H2SH2S+2KOHK2S+2H2OIJK2S+(x–1)SK2SxK2Sx+2H2SO42KHSO4+(x–1)S+H2SKEAISO2+2KOHK2SO3+H2OK2SO3+SK2S2O3GH2K2S2O3+I22KI+K2S4O6LK2S2O3+2H2SO42KHSO4+SO2+S+H2OEBA(B)1.(1)CuH(2)4CuSO4+3H3PO2+6H2O4CuH+3H3PO4+4H2SO4(3)2CuH+3Cl22CuCl2+2HCl(4)CuH+2HClHCuCl2+H2(若不是浓盐酸，则2CuH+2HClCuCl2+Cu+2H2)2.(1)Cr:N:H:O（原子个数比）＝(31.1/53.00):(25.1/14.00):(5.4/1.008):(38.4/16.00)＝1:3:9:4，A的化学式为CrO4(NH3)3。A的一种可能的结构式如右图所示。(2)+4；(3)不稳定；(4)(NH4)2CrO4+3H2O2+NH3CrO4(NH3)3+O2+4H2O3.(1)Ag2Se4AgCl+3Se+6NaOH2Ag2Se↓+Na2SeO3+4NaCl+3H2O(2)溶于水的物质有Na2SeO3、NaCl。过量的NaOH和Na2Se。(3)由于Se过量，...