试题与答案

化学实验基本操作在化学学习和研究中具有重要的作用.我们在进行化学实验时,下列情况

题型:问答题

题目:

化学实验基本操作在化学学习和研究中具有重要的作用.我们在进行化学实验时,下列情况应如何操行?

(1)连接玻璃管和胶皮管时,应该左手拿 ______(玻璃管或胶皮管),右手拿 ______(玻璃管或胶皮管),先把玻璃管口用水润湿,稍稍用力即可把玻璃管插入胶皮管.

(2)酒精灯不小心被碰倒,洒出的酒精在桌上燃烧起来,应该立即用 ______;

(3)在做可燃性气体的实验时,点燃可燃性气体之前一定要 ______.

答案:

(1)连接玻璃管和胶皮管时,要用右手拿玻璃管,用水湿润一下,左手拿胶皮管进行连接.故答案为:胶皮管;玻璃管.

(2)洒出的酒精在桌上燃烧起来,应该立即用湿抹布扑盖或用沙土盖灭.故答案为:湿抹布扑盖(或用沙土盖灭)

(3)点燃可燃性气体之前一定要检验气体的纯度,不纯时容易引起爆炸.故答案为:验纯

试题推荐
题型:完形填空

缺词填空(10分)

Sally was a student in a small town. It was going to be her mother’s birthday. She wanted to buy her a present that would be nice and useful but not e       .

She went s     after a quick and simple lunch. After she looked for about forty minutes, she found a shop that was selling cheap umbrellas(雨伞), and she d       to take a black one. She thought, “Mom can carry it when she is w________ clothes of any color.” So she bought a lovely black umbrella and took it to school with her until her class finished. On her way home on the train she felt h       So she went to the buffet car (餐车). She left the umbrella on her s     . But when she returned, it had gone. Sally began to cry. The o_______ passengers(乘客) felt very sorry for her and asked what was the matter. She told them the black umbrella she bought for her mother had gone, and she had to get off at the next station. After the three passengers h______      this , they asked her for her mother’s address(地址) so that(为了) they could send the umbrella to her if someone took it by mistake (弄错) and brought it b       

And now a week passed. Sally g______ a letter from her mother. It said, “Thank you very much for your lovely presents, but why do you send me three black umbrellas?”

查看答案
微信公众账号搜索答案