问题 填空题

实验室按下图所示装置制取CO2,并检验CO2的性质.试回答以下问题:

(1)实验开始前,先应检查装置A的______________。

(2)用装置A来制取CO2,所用的药品是____________和____________(写化学式)

(3)若要用装置B鉴定CO2,在B中应盛放的试剂名称是____________,当将标①和②的导管口连接时,B中看到的实验现象是______________________。

(4)若要用装置C证明CO2能与水反应生成碳酸,C中除有少量水外,应加入的试剂是_________________,当将标①和③的导管口连接时,C中看到的实验现象是________________。

(5)烧杯D中放有燃着的蜡烛如图所示,当将标①和④的导管口连接时,D中看到的实验现象是____________________________________。

(6)继续设计并进行有关CO2性质的探究实验,如装置E、F。先在装置E中放一个用空气充胀的气球,制取一瓶二氧化碳倒入E装置后,出现如F装置实验现象。请回答:该实验的目的是探究____________________________________。

答案

(1)气密性 (2)CaCO3;HCl (3)氢氧化钙,变浑浊

(4)紫色石蕊溶液,紫色变成红色 (5)底下蜡烛先熄灭(6)CO2的密度比空气大

(1)实验开始前,应先检查装置的气密性,防止装置漏气;

(2)实验室制取二氧化碳用大理石和稀盐酸反应制取,大理石的主要成分是碳酸钙;

(3)二氧化碳可使澄清的石灰水变浑浊,所以可用来检验二氧化碳;

(4)根据酸性物质可使紫色的石蕊试液变红分析解答;

(5)根据二氧化碳的密度比空气大,且不能燃烧、不能支持燃烧分析解答;

(6)根据图示分析实验目的. 

选择题
阅读理解

阅读理解。

     Playing is serious business for children. In fact, it's what they do best! Ask them why they do it, and kids

will probably say, "Because it's fun!" But it's much more than that. It's also good for them. 

     3 Studies show that from birth babies begin learning through play. They use their five senses to get know

their new world. Touching allows them to discover how different things feel. Brightly colored toys and clothing help develop a baby's sense of sight (视觉).

     When small children choose which toy to play with, they begin developing their abilities in making decisions.

     Children love toys that allow them to use their imagination. Sometimes an empty box is more fun than a

high-tech toy. That's because a box can become anything a child imagines it to be.

     Crayons, paints and Play-Doh (彩色塑泥) are also good because they allow children to crate. Traditional

building blocks teach important pre-math skills like problem-solving. 4. Playing doesn't become any less

important once children start school. Many valuable (有价值的) lessons about life are learned on the school

playground. Kids learn how to share, take turns and play by the rules.

1. What can children do best in their childhood? 

     ____________________________________________

2. What kind of toys do children love? 

     ____________________________________________

3. 将短文中画线的句子3译成汉语。

     ____________________________________________

4. 将短文中画线的句子4译成汉语。

     ____________________________________________

5. 请给短文拟一个适当的题目。

     ____________________________________________