题干

氧化亚铜(Cu2O)可用于船底防污漆,防止海生物对船舶设备的污损.现将Cu2O和Cu的固体混合物3.4g放入烧杯中,加入过量的质量分数为30%的稀硫酸20g,充分反应后,过滤、洗涤、干燥,得到2.4g固体.

已知:Cu2O+H2SO4=CuSO4+Cu+H2O

计算:原混合物中Cu2O和Cu的质量比(写出计算过程,结果用最简整数比表示).

上一题 下一题 0.0难度 选择题 更新时间:2014-08-20 10:12:55

答案(点此获取答案解析)

解:设原混合物中含Cu2O的质量为x

Cu2O+H2SO4=Cu+CuSO4+H2O

固体质量减少

同类题5

阅读理解。阅读下列四篇短文,从每小题后所给的A、B、C、D四个选项中,选出最佳选项。

    The Colonel(上校) asked Ashenden a good many questions and then suggested that he had particular qualifications for the Secret Service. Ashenden knew several European languages and the fact that he was a writer provided excellent cover: on the pretext(借口) that he was writing a book he could, without attracting attention, visit any neutral country.

    It was while they were discussing this point that the Colonel said, "You know you might get material that would be very useful to you in your work. I'll tell you an incident that occurred only recently. Very dramatic. A foreign government minister went down to a Mediterranean resort to recover from a cold and he had some very important documents with him that he kept in a dispatch case(公文箱). A day or two after he arrived, he picked up a beautiful blonde at some restaurant or other, and he got very friendly with her . He took her back to his hotel, and when he came to himself in the morning, the lady and the dispatch-case had disappeared. They had one or two drinks up in his room and his theory is that when his back was turned the woman slipped a drug in his glass.

    "Do you mean to say that happened the other day?" said Ashenden.

    "The week before last ."

    "Impossible," cried Ashenden. "Why! We've been putting that incident on the stage for sixty years, we've written it in a thousand novels. Do you mean to say that life has only just caught up with us?"

    "Well, I can guarantee the truth of the story." said the Colonel, "And believe me, the government has been put to no end of trouble by the loss of the documents."

    "Well sir, if you can't do better than that in the Secret Service," sighed Ashenden, " I'm afraid that as a source of inspiration to the writer of fiction, it's washout(失败)."