题目

The World Health Organization（WHO）planned to study the relationship between the eating habits of the people and the disease．Two doctors were chosen to make the study．They flew to Africa south of the Sahara and during the next two months visited ten countries．They found that serious diseases of poor eating, often mistaken for other diseases, existed in all parts of Africa．The diseases were similar and could therefore all be named kwashiorkor(恶性营养不良)．The diseased children are usually from one to four years old．As the illness progresses, the child’s stomach becomes s 常温下，向20 mL氢氧化钠溶液中逐滴加入0.2 mol·L－1的CH3COOH溶液，滴定曲线如图所示： (1)该氢氧化钠溶液的物质的量浓度为______________。 (2)在b点，c(Na＋)________c(CH3COO－)(填“＞”、“＜”或“＝”)。 (3)氢氧化钠溶液与CH3COOH溶液恰好完全反应的点位于曲线的________(填选项的编号)。 A．a点    B．b点 C．d点    D．a、b间的某点 E．b、d间的某点 (4)在d点，溶液中所有离子的浓度由大到小的顺序为 _____________________________________________________。