[题目]选择合适试剂完成甲.乙两组实验.甲组:检验含Fe3+的溶液中是否含有Fe2+,乙组:检验含Fe2+的溶液中是否含有Fe3+.下列试剂及加入试剂顺序能达到实验目的的是( )试剂选项甲组乙组A新制氯水.KSCN溶液NaOH溶液B酸性KMnO4溶液KSCN溶液CKOH溶液溴水D溴水酸性KMnO4溶液题目和参考答案——青夏教育精英家教网—

题目内容

【题目】选择合适试剂完成甲、乙两组实验。

甲组：检验含Fe3＋的溶液中是否含有Fe2＋；

乙组：检验含Fe2＋的溶液中是否含有Fe3＋。

下列试剂及加入试剂顺序能达到实验目的的是( )

试剂选项	甲组	乙组
A	新制氯水、KSCN溶液	NaOH溶液
B	酸性KMnO4溶液	KSCN溶液
C	KOH溶液	溴水
D	溴水	酸性KMnO4溶液

【答案】B

【解析】甲组，在Fe3＋存在的条件下检验Fe2＋，要排除Fe3＋干扰。所选试剂具备下列条件：一是能与Fe2＋发生有明显现象的反应；二是与Fe3＋不反应。只有酸性KMnO4溶液符合条件：5Fe2＋＋KMnO4－＋8H＋===5Fe3＋＋Mn2＋＋4H2O，实验现象是紫色变浅(或褪去)。乙组，在Fe2＋存在的条件下，检验Fe3＋，用KSCN溶液检验Fe3＋，Fe2＋无干扰。

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