问题
单项选择题
在制剂中作为金属离子络合剂使用的是
A．碳酸氢钠
B．焦亚硫酸钠
C．依地酸二钠
D．碳酸钠
E．氢氧化钠
答案
参考答案：C
解析：依地酸二钠是常见的金属离子络合剂。
搜题请搜索小程序“爱下问搜题”
在制剂中作为金属离子络合剂使用的是
A．碳酸氢钠
B．焦亚硫酸钠
C．依地酸二钠
D．碳酸钠
E．氢氧化钠
参考答案：C
解析：依地酸二钠是常见的金属离子络合剂。
（9分）我们生活在“水球”上，地球表面的70.8%被水覆盖。
（1）降雨是自然界中水循环的一个环节。 、 或这些气体在空气中反应后的生成物溶于雨水，会形成酸雨。
（2）请按要求写出水作为反应物的化学方程式：
①分解反应： ；
②化合反应： 。
（3）下表提供了在一定条件下，水能否与一些金属发生反应的信息。
①根据金属活动性顺序和表中的已知信息推断，镁与水蒸气 反应（选填“能”或“不能”）；
| 物质 | 钠与冷水 | 镁与冷水 | 镁与水蒸气 | 铁与冷水 | 铁与水蒸气 |
| 能否发 生反应 | 剧烈反应 | 缓慢反应 | ？ | 不反应 | 加热条件 下能反应 |
，所属基本反应类型是 反应；
③铁虽然常温下与水不反应，但铁制品在潮湿的环境中容易生锈。
某同学进行了如图所示实验，一周以后发现铁钉表面锈蚀。图中a、b、c三处锈蚀情况最严重的是 （选填字母），产生该现象的原因是 。
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| He was put in a small ward(病房) with another patient in a hospital. The ward had nothing 1 a small window that 2 to the outside world. His roommate was allowed to 3 in bed because some medical instruments would take some liquid out of his lung every afternoon, 4 he could only lie in bed all day long His roommate's bed was close to the 5 . Every afternoon, when sitting up by the window, his roommate would happily 6 him the ongoing scenes outside the window. His roommate's vivid descriptions made him feel like seeing the 7 scene with his own eyes. Never ever had he been so 8 for a look at the world outside the window as he was now. On a slightly rainy evening, he didn't feel satisfied with his 9 suddenly: Why could his roommate 10 the beautiful landscapes outside the window while he couldn't? At midnight, he stared at the ceiling and 11 into thought. All of a sudden, his roommate began coughing 12 and wanted to call the nurse, but failed to 13 the button of the bell. He 14 to be sound asleep, but after second thoughts he wanted to 15 the bell button. In his 16 of seconds, he shockingly found that his roommate had stopped 17 . On his roommate's death, he felt lonely, greatly miserable and guilty for not 18 his roommate. The doctor thought that he did not want to face a(n) 19 bed every day, so he promised to 20 another ward for him. Just the moment he was lifted onto the stretcher(担架), he spotted the scene outside the window-a pale wall. | ||||
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