问题 填空题

用化学方程式表示下列反应,并指明化学反应的类型

(1)铁在氧气中燃烧______;

(2)实验室用双氧水和二氧化锰制氧气______.

(3)把二氧化碳气体通进澄清石灰水中______.

其中化合反应的是______,分解反应的是______.

答案

(1)铁丝在氧气中燃烧生成四氧化三铁,反应的化学方程式为:3Fe+2O2

 点燃 
.
 
Fe3O4

(2)过氧化氢在二氧化锰的催化作用下生成水和氧气,反应的化学方程式为:2H2O2

 MnO2 
.
 
2H2O+O2↑.

(3)石灰水中的溶质是氢氧化钙,能与空气中的二氧化碳反应生成碳酸钙和水,反应的化学方程式为:CO2+Ca(OH)2═CaCO3↓+H2O.

上述反应中(1)符合“多变一”的特征,属于化合反应;(2)符合符合“一变多”的特征,属于分解反应.

故答案为:(1)3Fe+2O2

 点燃 
.
 
Fe3O4;(2)2H2O2
 MnO2 
.
 
2H2O+O2↑;(3)CO2+Ca(OH)2═CaCO3↓+H2O;(1);(2).

阅读理解

阅读理解。

     Two hours from the tall buildings of Manhattan and Philadelphia live some of the world's largest black

bears. They are in northern Pennsylvania's Pocono Mountains, a home they share with an abundance of

other wildlife.

     The streams, lakes, meadows, mountain ridges and forests that make the Poconos an ideal place for

black bears,have also attracted more people to the region. Open spaces are threatened by plans for housing

estates and important habitats are endangered by highway construction. To protect the Poconos' natural

beauty from irresponsible development, the Nature Conservancy (大自然保护协会) named the area one

of America's "Last Great Places"

     Operating out of a century-old schoolhouse in the village of Long Pond, Pennsylvania, the

conservancy's bud Cook is working with local people and business leaders to balance economic growth

with environmental protection. By forging partnerships with people like Francis Altemose, the Conservancy

has been able to protect more than 14,000 acres of environmentally important land in the area.

      Altemose's family has farmed in the Pocono area for generations. Two years ago Francis worked with

the Conservancy to include his farm in a county farmland protection program. As a result, his family's land

can be protected from development and the Altemoses will be better able to provide a secure financial future

for their 7-year-old grandson. Cook attributes the Conservancy's success in the Poconos to having a local

presence and a commitment to working with local residents

      "The key to protecting these remarkable lands is connecting with the local community," Cook said. "The

people who live there respect the land. They value quite forests, clear streams and abundant wildlife. They are

eager to help with conservation effort. For more information on how you can help The Nature Conservancy

protect the Poconos and the world's other"Last Great Places," please call 1-888-564 6864, or visit us on the

World Wide Web at www.tnc.org.

1. The purpose in naming the Poconos as one of America's " Last Great Places" is to ________.

A. gain support from the local community

B. protect it from irresponsible development

C. make it a better home for black bears

D. provide financial security for future generations

2. We learn from the passage that _______.

A. the population in the Pocono area is growing

B. wildlife in the Pocono area is dying out rapidly

C. the security of the Pocono residents is being threatened

D. farmlands in the Pocono area are shrinking fast

3. What is important in protecting the Poconos according to Cook?

A. The setting up of an environmental protection website

B. Support from organizations like The Nature Conservancy

C. Cooperation with the local residents and business leaders

D. Inclusion of farmlands in the region's protection program

4. The passage most probably is ________.

A. an official document

B. a news story

C. an advertisement

D. a research report

判断题