根据如图四个实验装置图回答问题
|
A、铁丝氧气中燃烧 |
B、测定空气中氧气含量 |
|
C、通电分解水 |
D、探究燃烧条件 |
A装置中集气瓶中的水______；
B装置中量筒中的水______；
C装置中水槽中的水______；
D装置中烧杯中的热水______．
（2）写出 B 装置中所发生反应的化学方程式______．
（1）铁丝氧气中燃烧实验中水的作用是冷却溅落融熔物，防止集气瓶炸裂；
测定空气中氧气含量实验中，通过水体积的变化测量得出O2体积；
通电分解水实验中水作为反应物；
探究燃烧条件实验中水的作用是隔绝空气，提供热量．
故答案为：冷却溅落融熔物，防止集气瓶炸裂；通过水体积的变化测量得出O2体积；作为反应物；隔绝空气，提供热量；
（2）磷燃烧生成五氧化二磷，该反应的化学方程式是4P+5O2
2P2O5 点燃 .
故答案为：4P+5O2
2P2O5． 点燃 .
| 阅读理解. | ||||||
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| 1. If you want to watch a football game, the best program for you would be ______. | ||||||
| A. TV play B. Sports C. Around the world D. Talk show | ||||||
| 2. The program of ______ will let you know much about western (西方的) countries. | ||||||
| A. Sisters B. Around China C. Around the world D. On TV next week | ||||||
| 3. If you want to know something about tigers, elephants and monkeys, the best program for you is ______. | ||||||
| A. Around China B. Animal world C. TV play D. Foreign arts | ||||||
| 4. English classroom is a program that ______. | ||||||
| A. lets you know something about classroom B. tells you something about students C. tells you something about school life D. teaches you English | ||||||
| 5. The program at the end of Channel 2 means (意思是) ______ on TV next week. | ||||||
| A. news B. programs C. people D. places | ||||||
