A.c(H + )=10 -pH ,所以pH=2与pH=1的CH 3 COOH溶液中,c(H + )分别为0.01mol/L、0.1mol/L,所以c(H + )之比为1:10,故A正确; B.任何电解质溶液中都存在电荷守恒和物料守恒,根据电荷守恒得c(Na + )+c(H + )=c(OH - )+c(HCO 3 - )+2(CO 3 2- ),根据物料守恒得2c(Na + )=(CO 3 2- )+c(HCO 3 - )>c(H 2 CO 3 ),所以得c(OH - )=c(HCO 3 - )+c(H + )+2c(H 2 CO 3 ),故B正确; C.如果溶液呈碱性,则c(OH - )>c(H + ),根据电荷守恒得c(Na + )>c(CH 3 COO - ),故C正确; D.醋酸是弱电解质,在水溶液里部分电离,溶液中氢离子浓度小于0.1mol/L,则水电离出的c(H + )大于1×10 -13 mol/L,故D错误; 故选D. |