试题与答案

(1)硬水中含有可溶性钙、镁化合物中的“钙”、“镁”指的是______(填“元素

题型:填空题

题目:

(1)硬水中含有可溶性钙、镁化合物中的“钙”、“镁”指的是______(填“元素”、“分子”、“原子”或“单质”).

(2)下列做法可以降低水的硬度的是______.(填番号)

A.吸附沉淀B.过滤C.活性炭吸附D.蒸馏E.投药消毒F.煮沸

(3)已调平的天平左右两边分别放有两个相同质量的烧杯,分别装有质量相等的碳酸钠粉末和碳酸氢钠粉末,向两边烧杯中加入相同质量、相同溶质质量分数的稀盐酸.充分反应后,天平的偏向是______.(填番号)

A.偏左B.偏右C.仍然平衡D.不能确定.

答案:

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                                                         The Chinese character " an"

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                                                        The Chinese character " fa"

1.               2.                3.                 4.                 5.             

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