可用来分离Fe3+和Al3+两种离子的试剂是（） A．盐酸 B．氢

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问题选择题

可用来分离Fe³⁺和Al³⁺两种离子的试剂是（）

A．盐酸

B．氢氧化钠溶液

C．氨水

D．硫氰化钾溶液

答案

答案：B

利用Al³⁺与过量的强碱形成，而Fe³⁺与OH^-形成Fe(OH)₃沉淀分离。应注意题目要求是分离而不是鉴别。

填空题

用括号里所给单词的正确形式完成句子。

1.This accident is a____ of one that happened here two weeks ago.( repeat)

2. I am____ to hear that your brother passed away.( sorrow)

3. He____ out sonnets in her praise.( thyme)

4. His character seems to have undergone a complete _____since his marriage.( transform)

5. She was ______recognizable as the girl I had known at school. (bare)

6. I have asked the_____ to look me out books on butterflies. (library)

7. The acting chairman did everything_____.(appropriate)

8. The____ includes an allowance of 80 dollars for books.( schol ar)

9. The ____ accompanied her singing.( piano)

10. It is a train of twenty empties and ten ____.(load)

问答题

[问题2] IPSec的密钥管理包括密钥的确定与分发。IPSec支持 (2) 和 (3) 两种密钥管理方式。试比较这两种方式的优缺点。