题干

 一次化学兴趣小组活动时,罗莉在实验室制取了一种初中化学中常见的气体,收集在三个集气瓶中,让李刚通过实验确定该气体的成分,李刚进行了下面的实验。请根据实验步骤和现象,将你的推断结果及结论填入下表空格中,并回答问题。

实 验 步 骤实 验 现 象推断结果及结论
(1)取一瓶气体,闻其气味。无气味可能是H2、O2、N2、CO、CO2、CH4
(2)移开另一瓶的玻璃片,将一燃着的木条缓慢伸入瓶中。瓶口处未见火焰一定不是____
木条的火焰熄灭一定不是____
(3)向第三个瓶中注入少量澄清石灰水,振荡。石灰水变浑浊一定是____
在进行实验(3)时,除了使用澄清的石灰水外,还可用____来确定该气体。
请写出实验步骤、实验现象和反应方程式。
(4)____                    ____                                反应方程式____
上一题 下一题 0.0难度 选择题 更新时间:2015-12-15 04:59:57

答案(点此获取答案解析)

H2\u3001CO\u3001CH4,O2,CO2,\u7d2b\u8272\u77f3\u854a\u8bd5\u6db2,\u5411\u7b2c\u4e0

同类题5

任务型阅读

    There is no doubt that the first day of school can be crazy for most of students. New kids wander (徘) around in circles, waiting for the opening of the school door. The school nurse needs your medical records. ____ The freshmen are running in all directions, looking for their new classrooms.

    How can you overcome the first-day chaos? If you will go to a new school, try to arrange a visit before classes begin. Explore any areas, such as the playground, library, or school labs.____

    Get one and read it before your school, starts-then keep it in your school bag until you're familiar with your new surroundings. Your first day is also the time to bring in school supplies and books.

    You should arrange your schoolbag well the night before you go to school so that you won't look for what you need at the last minute.

    Did you try on eight different coats before deciding on what to wear?____ The best choice is to wear what makes you feel good, whether it is a new coat or an old sweater. If you plan to wear a pair of shoes, make sure they fit you well.

    ____ Some start with a gathering, while others may jump right into the first-period class. You'll meet your new teachers, and they will probably give you an overview of the courses, class rules, what the semester will be like, what supplies you'll need, and expectations of your performance and behavior. Some teachers will jump into their first lesson, while others may have some activities.____

A. Some schools even offer maps.

B. But you forget to bring it with you.

C. It all depends on the class and teacher.

D. Don't depend on your parents any more.

E. Each school has different opening-days.

F. You can also try to ask the teachers for help.

G. Lots of students have difficulty deciding on what to wear on the first day of school.