试题与答案

鸡蛋壳的主要成分是碳酸钙。某学生想测定鸡蛋壳中碳酸钙的质量分数,取15g干燥的碎

题型:计算题

题目:

鸡蛋壳的主要成分是碳酸钙。某学生想测定鸡蛋壳中碳酸钙的质量分数,取15g干燥的碎鸡蛋壳放入烧杯中,向其中加入了40g稀盐酸恰好完全反应(假设鸡蛋壳中除碳酸钙外的其他成分都不溶于水,且不与稀盐酸反应),反应后烧杯中物质的总质量50.6g。计算鸡蛋壳中碳酸钙的质量分数(结果保留1位小数)。

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解析: 债的担保方式包括:抵押、质押、留置、保证,定金等,预付款只是一种付款方式,不能起到担保的作用,不是债的担保方式,故选C。

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B.However

C.Such

D.So

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