问题
选择题
We ________ some robots in the next few months, and there__________ in the office, too.[ ]
A. will have;will have
B. have;will have
C. will have;will be
D. have;will be
答案
答案:C
We ________ some robots in the next few months, and there__________ in the office, too.[ ]
A. will have;will have
B. have;will have
C. will have;will be
D. have;will be
答案:C
(5分)某校课外活动小组的同学在测定由MgCl2和NaCl组成的固体混合物的组成时,进行了如下实验。取20克固体配成200克溶液,平均分成四份,然后分别加入一定质量分数的NaOH溶液,所得实验数据见下表:
实验一 | 实验二 | 实验三 | 实验四 | |
固体混合物溶液的质量/g | 50 | 50 | 50 | 50 |
加入NaOH溶液的质量/g | 10 | 20 | 30 | 40 |
生成沉淀的质量/g | 1 | m | 2.9 | 2.9 |
(1)m= ;
(2)20g原固体混合物溶液和足量NaOH溶液反应最多生成沉淀的质量 g;
(3)在实验三中,完全反应后所得溶液中氯化钠的质量分数是多少?(结果保留一位小数,写出计算过程) 。