问题 填空题

(7分)空气是一种十分重要的天然资源。

(1)空气成分按体积计算,含量最多的是________(填写化学式)。

(2)实验室可通过多种途径制取氧气,如分解过氧化氢、加热高锰酸钾、电解水等,因为这三种物质都含有_________元素(填元素符号);从降低能量消耗上思考,你选择的实验室制取氧气的方法是_________________。

(3)保护空气,提倡“低碳”,减少温室效应,是我们必须关注的问题。科学家正在研究如下图所示的二氧化碳新的循环体系。

从图中分析得出的下列结论中,正确的是      (填字母序号)。

A.二氧化碳也是一种重要的资源       

B.利用降温、加压将二氧化碳分离是化学变化        

C.二氧化碳与氢气在复合催化剂下反应产物是混合物

D.液化石油气、汽油、甲醇等物质燃烧都有二氧化碳产生

(4)酸雨的形成主要是二氧化硫与水作用产生的亚硫酸(H2SO3)被空气中的氧气氧化为硫酸(H2SO4)的缘故。该氧化反应的化学方程式为                 

(5)“绿色化学”的特点之一是“零排放”。一定条件下,一氧化碳和氢气可以按照不同比例反应,若只生成一种产物就能实现“零排放”,符合这一要求的产物是            (填字母序号)。

A.甲醇(CH4O)   B.甲醛(CH2O)    C.乙醇(C2H6O)  D.乙醛(C2H4O)

答案

⑴ N2  ⑵ O  分解过氧化氢 ⑶ ACD   ⑷ 2H2SO3 + O2 ==2H2SO4  ⑸A、B

:(1)空气中含量最多的是氮气.

故答案为:N2

(2)过氧化氢、高锰酸钾、水的化学式分别是:H2O2、KMnO4、H2O,可见这三种物质都含有氧元素;其中高锰酸钾制取氧气需要加热,电解水制取氧气需要通电,只有过氧化氢制取氧气用二氧化锰做催化剂即可,所以从降低能量消耗上思考,应选择分解过氧化氢的方法制取氧气.

故答案为:O;分解过氧化氢;

(3)从图中分析得出的结论中,A、二氧化碳也是一种重要的资源是正确的;C、二氧化碳与氢气在复合催化剂下反应产物是混合物是正确的;D、液化石油气、汽油、甲醇等物质燃烧都有二氧化碳产生是正确的,而答案B属于物理变化,因此是错误的.

故答案为:ACD;

(4)二氧化硫与雨水作用生成的亚硫酸(H2SO3),亚硫酸在空气中被氧气逐渐氧化生成酸性更强的硫酸(H2SO4).这一过程的两个化学方程式为:SO2+H2O═H2SO3;2H2SO3+O2═2H2SO4

故答案为:SO2+H2O═H2SO3;2H2SO3+O2═2H2SO4

(5)在反应A、CO+2H2=甲醇(CH4O);B、CO+H2=甲醛(CH2O)中,一氧化碳和氢气按照不同比例反应,且只生成一种产物,实现了“零排放”.

故选A、B.

阅读理解

阅读理解

     I travel a lot, and I find out different "styles" (风格) of directions every time 1 ask "How can I get to

the post office?"

     Foreign tourists are often confused (困惑) in Japan because most streets there don't have names; in

Japan, people use landmarks (地标) in their directions instead of street names. For example, the Japanese will say to travelers, "Go straight down to the corner. Turn left at the big hotel and go past a fruit market.

The post office is across from the bus stop."

     In the countryside of the American Midwest, there are not usually many landmarks. There are no

mountains, so the land is very flat; in many places there are no towns or buildings within miles. lnstead of

landmarks, people will tell you directions and distances. In Kansas or Iowa, for example, people will say, "Go north two miles. Turn east, and then go another mile."

     People in Los Angeles, California, have no idea of distance on the map; they measure distance in time, not miles. "How far away is the post office?" you ask. "Oh," they answer, "it's about five minutes from here." You say, "Yes, but how many miles away is it?" They don't know.

     It's true that a person doesn't know the answer to your question sometimes. What happens in such a

situation? A New Yorker might say, 'Sorry, I have no idea." But in Yucatan, Mexico, no one answers "I

don't know." People in Yucatan believe that "I don't know" is impolite, They usually give an answer,

often a wrong one. A tourist can get very, very lost in Yucatan!

1. When a tourist asks the Japanese the way to a certain place they usually _________

A. describe the place carefully

B. show him a map of the place

C. tell him the names of the streets

D. refer to recognizable(可辨认的) buildings and places

2. What is the place where people measure distance in time?

A. New York.  

B. Los Angeles.  

C. Kansas.  

D. Iowa.

3. People in Yucatan may give a tourist a wrong answer ________

A. in order to save time  

B. as a test 

C. so as to be polite  

D. for fun

4. What can we infer from the text?

A. It's important for travelers to understand cultural differences.

B. It's useful for travelers to know how to ask the way properly.

C. People have similar understandings of politeness.

D. New Yorkers are generally friendly to visitors.

判断题