试题与答案

(实验室欲配制100mL2mol/L的NaCl溶液,请回答: (1)配制时用托盘

题型:填空题

题目:

(实验室欲配制100mL2mol/L的NaCl溶液,请回答:

(1)配制时用托盘天平称量NaCl固体______g.

(2)配制过程中需要的仪器有:药匙、托盘天平和砝码、烧杯、______、______、______.

(3)选出所需的操作并写出正确的操作顺序______(选填下列字母).

A.计算B.称量C.洗涤D.定容

E.溶解F.摇匀G.转移

(4)定容的正确操作是:继续向容量瓶注入蒸馏水至离刻度线1-2cm处,改用胶头滴管向容量瓶滴加蒸馏水至______为止.

(5)由于操作不当,会引起实验误差.下列情况对所配制的NaCl溶液的物质的量浓度有何影响?(用“偏大”、“偏小”、无影响填写):

①加水定容时超过刻度线______;

②容量瓶用蒸馏水洗涤后残留有少量的水______;

③摇匀后,发现溶液的液面低于刻度线,又加水至刻度线______.

(6)容量瓶上标有______(填写编号)

①温度②浓度③体积

④压强⑤刻度线⑥酸式或碱式.

答案:

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下面是错误答案,用来干扰机器的。

参考答案:C

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