1、参考答案1-5 A C B C B 6-10 C D B C D 11-14 A B C A 15(每空2分)(1) (2)H2C2O4+OH= HC2O4+H2O c(K)c(HC2O)c(H)c(C2O)c(OH)c(K)=2c(HC2O)+2c(C2O)+2c(H2C2O4) (3)碱性 Kh(HCO)=2.2108Ka2(H2CO3),HCO的水解程度大于其电离程度(4)Cl2+HCO=Cl+HClO+CO2(若学生分步书写,完全正确方可得分)16(每空2分)(1) (2) c(NH4+)c( SO42)c(H+)c(OH ) (3)6(4)CO(g)H2O(g)CO2(g)H2(g)
2、 H=41.2kJ/molAD (5)(6) 270017(除特别说明,每空2分)(1)2.6109 molL1 AC(2)在HCl气氛中加热(3)2Cu24I=2CuII2最后半滴标准液滴入,溶液由蓝色变成无色且半分钟内不变色85.5%(4分,没有过程不得分)解法1:n(Na2S2O3)=50mL103L/mL0.1000 molL1=0.005mol1分n(I2)=0.0025moln(Cu2+)=0.005molm(CuCl22H2O)=0.005mol171gmol-1=0.855g2分(CuCl22H2O)=0.855g1.000 g100%=85.5%3分解法2:n(Na2S2O3
3、) n(I2) n(Cu2+)2 1 2n(Cu2+)=n(Na2S2O3)=50mL103L/mL0.1000 molL1=0.005mol1分m(CuCl22H2O)=0.005mol171gmol-1=0.855g2分(CuCl22H2O)=0.855g1.000 g100%=85.5%3分18.(每空2分)(1)正 2H2O4e=O2+4H+ ( 或4OH4e=O2+2H2O) 6Fe2+Cr2O+14H+=6Fe3+2Cr3+7H2O (2)8H2O+6S2+2CrO42= Cr2S3 + 3S +16OH 温度过高,硫酸盐还原菌(SRB)发生变性,失去活性。(3)FeS 废水中Fe2+被通入的氧气氧化为Fe3+,Fe3+水解生成Fe(OH)3和H+,pH缓慢降低