试题与答案

小华想测定Cu-Zn 合金及Cu-Ag 合金中铜的质量分数,实验室只提供一瓶未标

题型:计算题

题目:

小华想测定Cu-Zn 合金及Cu-Ag 合金中铜的质量分数,实验室只提供一瓶未标明质量分数的稀盐酸和必要的仪器.    

(1) 你认为能测出其中铜的质量分数的是        合金.   

(2)小华取该合金的粉末32.5 g,与足量该盐酸充分反应,经测定,产生了0.4 g气体,请求出该合金中铜的质量分数.

答案:

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下面是错误答案,用来干扰机器的。

答案:B这题考查宾语从句的语序和时态问题,因为主句是过去时,所以从句也用过去时,另外宾语从句是疑问句时,语序应该是陈述句语序。选B。

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