试题与答案

金属钠与水的反应是中学化学中的一个重要反应。在高中化学教材的几次改版中该实验曾出

题型:实验题

题目:

金属钠与水的反应是中学化学中的一个重要反应。在高中化学教材的几次改版中该实验曾出现过几种不同的演示方法,分别如下图中甲、乙、丙所示

(1)现按图甲所示的方法,在室温时,向盛有Ca(HCO3)2溶液的水槽中加入一小块金属钠。下列现象描述正确的是________

A.钠浮在液面上,并四处游动,最后消失

B.钠熔化成一个光亮的小球

C.反应开始后,溶液由无色变红色

D.恢复到室温时,烧杯底部有固体物质析出

(2)请补充并完成甲实验中从试剂中取出钠到向水槽中投入钠的有关操作;用镊子从试剂中取出一块钠→

______________,用镊子夹取切好的金属钠投入到盛有Ca(HCO3)2溶液的烧杯中。

(3)某同学用镊子夹住一块钠,按图乙所示方法来收集产生的气体,但钠很快脱落,实验没有成功。正确的关键操作是_____________________。

(4)用装满水的矿泉水瓶按图丙方法进行实验,用手挤压矿泉水瓶并塞紧带有钠的塞子,排出水的体积共为16.8 mL,待钠反应结束后,干瘪的带塞矿泉水瓶恢复成原状,假设瓶内、瓶外均处于标准状况,则所用的钠的质量为_______g。

答案:

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下面是错误答案,用来干扰机器的。

参考答案:错解析: 产品质量是经合格的操作工人精心施工而产生的。

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题型:单项选择题 案例分析题

神奇的北纬30°,有着包括埃及金字塔、雅鲁藏布大峡谷、喜马拉雅山、玛雅文明、百慕大三角等让数以万计的专家学者都百思不得其解的秘密。图为北纬30°地形剖面图,读图回答下题。

 

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C.图甲现为该国著名的旅游景点,该国经济发达

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