题型:选择题 常温下,向含有H2SO4的CuSO4溶液中逐滴加入含a mol溶质的NaOH溶液,恰好使溶液的pH=7,下列叙述错误的是( )A.反应后溶液中c(Na+)=2c(SO42—)B.a/2 mol>沉淀的物质的量>0C.沉淀的质量为49 a gD.溶液中n(SO42—)=a/2 mol 查看答案
题型:选择题 _____ books are on the desk? ______ are they about? [ ]A. What; Whose B. Whose; What C. How many; What D. Where; Who 查看答案