现配制溶质质量分数为5%的NaCl溶液100g,下列操作错误的图示是( )

现配制溶质质量分数为5%NaCl溶液100g,下列操作错误的图示是(  )

A

取用氯化钠固体  B

量取蒸馏水

C

氯化钠溶解  D

溶液裝瓶贴签

答案

【考点】32:实验操作注意事项的探究.

【分析】A、取用氯化钠固体,不能用手,应用药匙,会污染药品;

B、取用液体时:①试剂瓶瓶口要紧挨量筒口,防止液体流出;②标签向着手心,防止液体流出腐蚀标签;

C、氯化钠溶解,用玻璃棒不断的进行搅拌,以加速溶解;

D、配制完的溶液装配贴签,防止变质、方便使用.

【解答】解:A、实验室的药品有毒或腐蚀性,图中操作错误,故A错误;

B、取用液体时,注意:试剂瓶瓶口要紧挨量筒口;②标签向着手心,图中操作正确,故B正确;

C、氯化钠溶解,用玻璃棒不断的进行搅拌,以加速溶解,图中操作正确,故C正确;

D、配制完的溶液装配贴签,防止变质、方便使用,图中操作正确,故D正确.

故选:A

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