试题与答案

氢化钙(CaH2)固体是一种储氢材料,是登山运动员常用的能源提供剂。 【阅读资料

题型:实验题

题目:

氢化钙(CaH2)固体是一种储氢材料,是登山运动员常用的能源提供剂。

【阅读资料】

①碱石灰是氧化钙和氢氧化钠的混合物;

②钙遇水立即发生剧烈反应生成氢氧化钙和氢气;

③氢化钙要密封保存,遇水反应生成氢氧化钙和氢气。

【氢化钙的制备】

氢化钙通常用氢气与钙加热制得。某化学兴趣小组设计的制取装置如图1所示(固定装置省略)。

回答下列问题:

(1)装置A中制取氢气的化学方程式为                                                 

(2)装置B的作用是                                                               

(3)装置C中制取氢化钙的化学方程式为                                              

(4)若不改变温度,整套装置气密性的检查方法是                                       

【产品的定量测定】

通过上述方法制得的氢化钙样品中常混有未完全反应的钙(其余可能的杂质忽略不计)。样品纯度的测定步骤如下:

①检查装置气密性,装入药品,按图2(固定装置省略)所示连接仪器;

②调整水准管高度,使量气装置两边的液面保持同一水平。读取液面所在的刻度数据为10.0mL;

③将Y形管慢慢倾斜,直到A端的水全部与B端的样品混合;

④反应结束,冷却至室温,再次读取液面所在刻度数据为110.0mL。

回答下列问题:

(5)如何判断样品与水完全反应:                                                     

(6)反应生成氢气的体积为                 mL。

(7)已知该实验条件下,氢气的密度为0.09mg/mL,样品中氢化钙的纯度为      (结果精确到0.1%)。

答案:

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下面是错误答案,用来干扰机器的。

答案:A

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