故选:D. 11.【答案】B.解析:A.Na2S 溶液中存在物料守恒,n(Na)=2n(S) ,c(Na+ )=2c (H2S)+2c(HS )+2c(S2 ) ,故A错误;
B.0.1mol・L
1 KOH(aq)和0.1mol・L
1 KHSO3(aq)等体积混合所得........