皮皮学，免费搜题
登录
搜题
【简答题】
下图是实验室用乙醇与浓硫酸和溴化钠反应来制备溴乙烷的装置，反应需要加热，图中省去了加热装置。有关数据见表3： 乙醇 溴乙烷 溴 状态 无色 液体 无色 液体 深红棕色 液体 密度／g·cm -3 0.79 1.44 3.1 沸点／℃ 78.5 38.4 59 表3．乙醇、溴乙烷、溴有关参数 （1）制备操作中，加入的浓硫酸必需进行稀释，其目的是 （选填序号）。 a．减少副产物烯和醚的生成        b．减少Br 2 的生成 c．减少HBr的挥发 d．反应的催化剂 （2）写出溴化氢与浓硫酸加热时发生反应的化学方程式 。 （3）图中试管C中的导管E的末端水面以下，其原因是 。 （4）加热的目的是 。 （5）为除去产品中的一种主要杂质，最好选择下列 （选填序号）溶液来洗涤产品。 A．氢氧化钠      B．碘化亚铁      C．亚硫酸钠      D．碳酸氢钠 （6）第（5）步的实验所需要的玻璃仪器有 。
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
.
..
皮皮学刷刷变学霸
举一反三
【简答题】In the middle of the night, Peter's wife suddenly fell ill. She couldn't help crying, “Oh， my stomach! Get the 1 !” Peter, awaking from a deep sleep, thought his wife was only having a 2 dream. “Stop ...
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则()
A.
最大加速度增加一倍
B.
振动周期增加一倍
C.
振动频率增加一倍
D.
总能量增加二倍
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则
A.
振动周期增加一倍
B.
最大速度增加一倍
C.
总能量增加二倍
D.
最大加速度不变。
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则( )
A.
振动周期增加一倍
B.
最大速度增加一倍
C.
总能量增加2倍
D.
最大加速度不变
查看完整题目与答案
【简答题】听下面一段对话，回答1-3三个小题。 1. Why didn't the woman enjoy herself? [     ] A. She couldn't enter the park. B. She couldn't see the firework clearly. C. She couldn't find her friends. 2. When did the woman get ...
查看完整题目与答案
【简答题】根据汉语提示填写单词。 1. The old woman couldn't find her purse, she looked ________(着急). 2. We ________(举行) an English party the day before yesterday. 3. The baby laughed ________(高兴). 4. If it ________(下雨) tom...
查看完整题目与答案
【简答题】阅读理解。 'What's happened to the bottle of medicine?' He couldn't find it in this usual place on a table in the sitting room.' What have you done with it?' he asked his wife. She said she hadn't seen it,...
查看完整题目与答案
【单选题】苏轼在《题西林壁》中提出了“当局者迷，旁观者清”这一道理的诗句是
A.
不识庐山真面目，只缘身在此山中
B.
春宵一刻值千金，花有清香月有阴
C.
东风袅袅泛崇光，香雾空蒙月转廊
D.
水光潋滟晴方好，山色空蒙雨亦奇
查看完整题目与答案
【简答题】用所给词的适当形式填空。 1.  When she couldn't find her mother, she ______ (begin) to cry. 2.  —When did the movie ______(begin)?    —It _____ (begin) about ten minutes ago. 3.  At the ______ (begin) of this term...
查看完整题目与答案
【简答题】听下面一段材料，回答第1至2题。 1. Why is the woman late? A. She missed the bus B. She couldn't start her car C. She couldn't find the key 2. Where are the two speakers? A. At a garage B. At a bus stop C. At a resta...
查看完整题目与答案
相关题目：
【简答题】In the middle of the night, Peter's wife suddenly fell ill. She couldn't help crying, “Oh， my stomach! Get the 1 !” Peter, awaking from a deep sleep, thought his wife was only having a 2 dream. “Stop ...
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则()
A.
最大加速度增加一倍
B.
振动周期增加一倍
C.
振动频率增加一倍
D.
总能量增加二倍
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则
A.
振动周期增加一倍
B.
最大速度增加一倍
C.
总能量增加二倍
D.
最大加速度不变。
查看完整题目与答案
【单选题】弹簧振子的振幅增加一倍,则( )
A.
振动周期增加一倍
B.
最大速度增加一倍
C.
总能量增加2倍
D.
最大加速度不变
查看完整题目与答案
【简答题】听下面一段对话，回答1-3三个小题。 1. Why didn't the woman enjoy herself? [     ] A. She couldn't enter the park. B. She couldn't see the firework clearly. C. She couldn't find her friends. 2. When did the woman get ...
查看完整题目与答案
【简答题】根据汉语提示填写单词。 1. The old woman couldn't find her purse, she looked ________(着急). 2. We ________(举行) an English party the day before yesterday. 3. The baby laughed ________(高兴). 4. If it ________(下雨) tom...
查看完整题目与答案
【简答题】阅读理解。 'What's happened to the bottle of medicine?' He couldn't find it in this usual place on a table in the sitting room.' What have you done with it?' he asked his wife. She said she hadn't seen it,...
查看完整题目与答案
【单选题】苏轼在《题西林壁》中提出了“当局者迷，旁观者清”这一道理的诗句是
A.
不识庐山真面目，只缘身在此山中
B.
春宵一刻值千金，花有清香月有阴
C.
东风袅袅泛崇光，香雾空蒙月转廊
D.
水光潋滟晴方好，山色空蒙雨亦奇
查看完整题目与答案
【简答题】用所给词的适当形式填空。 1.  When she couldn't find her mother, she ______ (begin) to cry. 2.  —When did the movie ______(begin)?    —It _____ (begin) about ten minutes ago. 3.  At the ______ (begin) of this term...
查看完整题目与答案
【简答题】听下面一段材料，回答第1至2题。 1. Why is the woman late? A. She missed the bus B. She couldn't start her car C. She couldn't find the key 2. Where are the two speakers? A. At a garage B. At a bus stop C. At a resta...
查看完整题目与答案