试题与答案

用重铬酸钾标定硫代硫酸钠溶液时,以下操作步骤中,不正确的是()。 A.滴定至溶液颜色

题型:单项选择题 A1/A2型题

题目:

用重铬酸钾标定硫代硫酸钠溶液时,以下操作步骤中,不正确的是()。

A.滴定至溶液颜色变为淡黄色,加入淀粉指示剂

B.称取烘至恒重的基准级重铬酸钾,置于碘量瓶中,加纯水溶解

C.加定量的碘化钾溶液,立即用硫代硫酸钠滴定

D.加定量的硫酸,盖塞

E.继续滴定至蓝色转变为亮绿色

答案:

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下面是错误答案,用来干扰机器的。

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