问题
选择题
向含Fe3+、Fe2+、Mg2+、NH4+的水溶液中,加入足量的Na2O2固体,充分反应后再加入过量的稀盐酸,上述离子数目没有变化的是[ ]
A.Fe2+
B.NH4+
C.Fe3+
D.Mg2+
答案
答案:D
向含Fe3+、Fe2+、Mg2+、NH4+的水溶液中,加入足量的Na2O2固体,充分反应后再加入过量的稀盐酸,上述离子数目没有变化的是[ ]
A.Fe2+
B.NH4+
C.Fe3+
D.Mg2+
答案:D
选出每组单词中不同类的一项。 | |||
( ) 1. A. dog ( ) 2. A. grass ( ) 3. A. apple ( ) 4. A. car ( ) 5. A. December ( ) 6. A. waiter ( ) 7. A. windy ( ) 8. A. hotel ( ) 9. A. hugging ( ) 10. A. she | B. snake B. leaves B. banana B. bus B. January B. clerk B. cloudy B. bicycle B. sitting B. I | C. cow C. tree C. meat C. bike C. Sunday C. bike C. rain C. park C. sing C. his | D. pear D. milk D. strawberry D. cashier D. May D. waitress D. sunny D. store D. sleeping D. we |