问题 实验题

请你完成对实验室制取二氧化碳的实验探究。

(1)选择药品。下表是对四组药品进行实验的记录:

组别药品实验现象
块状石灰石和稀盐酸产生气泡速率适中
石灰石粉末和稀盐酸]产生气泡速率很快
块状石灰石和稀硫酸产生气泡速率缓慢并逐渐停止
碳酸钠粉末和稀盐酸产生气泡速率很快
 

从制取和收集的角度分析,一般选择第        组药品(填字母序号,下同),该组药品发生反应的化学方程式为                                          

(2)选择装置。选择               发生装置。

(3)制取气体。选择   装置收集二氧化碳,其验满方法是                     

(4)气体检验。将生成的气体通入紫色石蕊溶液中,溶液变红,确定该气体是二氧化碳。这种检验方法是否正确?若正确请说明理由,若不正确请写出正确的检验方法。                          

答案

(1)①     CaCO3+2HCl=CaCl2+H2O+CO2

(2)B

(3)D        将燃着的木条接近集气瓶口,木条熄灭则满

(4)不正确,将气体通入澄清石灰水,若变浑浊则是二氧化碳,否则不是二氧化碳。

题目分析:(1)实验室制取二氧化碳要求速度适中,所以应选①;反应的化学方程式为:CaCO3+2HCl=CaCl2+H2O+CO2

(2)该反应中反应物的状态为固态和液态,反应条件为常温。所以应选择的发生装置为B。

(3)二氧化碳能溶于水,不适用于排水法收集;二氧化碳的密度比空气大,适用于向上排空气法。所以其收集装置应选D。其验满的方法是:将燃着的木条接近集气瓶口,如果木条熄灭说明气体已收集满。

(4)这种方法不正确。二氧化碳的检验方法是:将气体通入澄清石灰水,若变浑浊则是二氧化碳,否则不是二氧化碳。

问答题 论述题
单项选择题

Greenstreak is an international non-profit agency dedicated to the preservation of natural habitats and the animals that rely on them. With offices in over 20 countries, Greenstreak is one of the leading organizations in the fight to preserve our world’s precious resources. Since 1946, Greenstreak has worked with nonprofit groups, world leaders in politics, business and industry, and government organizations like the United Nations to change the way people think about conservation.
As part of our mission, Greenstreak offers a number of courses for interested individuals and groups of all levels on a range of topics related to ecology, biology, green riving, and conservation. We have a great deal of experience speaking to youth groups, schools, university symposia, and government conferences. In the interest of spreading the important message about honoring our planet, Greenstreak can customize a presentation to the specific needs of any group. If your organization is interested in having Greenstreak show up at your next event, please call your local Greenstreak office or visit us on the Web at www.greenstreak.org.
From: bartmanstead@schools.greenbrier.alberta.ca
To: events@greenstreak.org.ca
Date: April 13, 01:40.23 p.m.
Good morning! My name is Bart Manstead, and I’m a science teacher at Greenbrier Middle School in Greenbrier, Alberta, Canada. We are arranging a special science fair for Earth Day this year at the school. I’m currently in the process of organizing guest speakers for the event, and I would like to extend an invitation to Greenstreak to be our Guest of Honor.
We are a regional middle school for students in 5th through 8th grades (about 11-14 years old) for the city of Greenbrier and a number of surrounding districts. We have approximately 3,500 students at the school.
In order to determine if Greenstreak can provide what we’re looking for, I would appreciate it if you could send me more information about your presentations. Obviously, any kind of seminar would have to fit the needs of our students, the limits of our facilities, and the school budget. However, we would be delighted to arrange for you to be present at our science fair. Please reply at your convenience with the requested information. Thanks!
Bart Manstead

What does Mr. Manstead request in his e-mail

A.A Greenstreak representative to come to the school

B.More information on Greenstreak’s presentations

C.Information about Greenbrier Middle School

D.A copy of a previous Greenstreak presentation