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当前学科：中级电厂水化验员
题目：
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已知某溶液可能是由NaOH、Na
2
CO
3
、NaHCO
3
或它们的混合物组成，现用浓度为c的盐酸滴定此溶液，用甲基橙作指示剂，需V1mL，同样的试样用酚酞作指示剂，需V2mL，若V1＞0，V2＝0，则溶液的组成可能是（）。
A . A、NaHCO
3
；
B . B、Na
2
CO
3
＋NaHCO
3
；
C . C、Na
2
CO
3
＋NaOH；
D . D、Na
2
2
CO
3
。
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