_______ you’ve got such a good chance, you might as well make full use of it. A. Even if B. Now that C. As soon as D. As though 答案:B
我国约在南北朝时就开始冶炼黄铜.黄铜是铜和锌的合金(Cu-Zn),它可用来制造及其、电器零件及日用品.为了测定某黄铜样品中锌的质量分数(不考虑黄铜中的其他杂质),现将15 mL稀盐酸分三次加入到5 g黄铜样品粉末中,每次充分反应后,测定生成氢气的质量,实验数据见下表:
试求:
(1)m=________.
(2)此黄铜样品中锌的质量分数是多少?