问题 填空题

(10分)化学与生产、生活息息相关。请用所学的知识回答下列问题:

(1)人呼吸作用产生的CO2若不能及时排出,滞留在血液中会使血液的pH        (选填“不变”、“变大”或“变小”)。

(2)在汽车尾气排放口加装“催化净化器”,可让尾气中的有害气体CO、NO发生如下反应:

2CO + 2NO  催化剂  N2 + 2X ,则X的化学式为              

(3)天然气是最常用的化石燃料之一,主要成分是甲烷(CH4),其燃烧的化学方程式

为:                                                         

(4)下列行为安全、可取的是                (填序号)。

A.小心使用浓酸浓碱

B.使用燃气热水器沐浴时打开排气扇

C.霉变的大米洗净后继续食用

D.进入久未开启的菜窖前做灯火试验

答案

(1)变小 (2)CO2  (3)CH4+ 2O2点燃CO2 + 2H2O    (4)ABD

题目分析:(1)二氧化碳会与水结合形成碳酸,所以血液的酸性会增强,则其pH会变小。

(2)根据质量守恒定律可知:反应前后原子的种类及数目不变。所以每个X的分子中含一个碳原子和两个氧原子,其化学式为CO2

(3)甲烷(CH4)燃烧的化学方程式为:CH4+ 2O2点燃CO2 + 2H2O    

(4)A浓酸或浓碱一般都有较强的腐蚀性,所以使用时要小心。此项正确。B燃气热水器中的一氧化碳气体有毒,所以使用时应打开排气扇通风;此项正确。C.霉变的大米内含有毒素,所以不能食用洗;此项不正确。D.久未开启的菜窖内含有二氧化碳气体,所以进入之前做灯火试验。如蜡烛燃烧的较弱或熄灭,则说明二氧化碳超标。此项正确。所以应远ABD。

多项选择题
阅读理解

阅读理解。

    Ever since news of widespread food recalls caused by a carcinogenic dye(颜料) broke, there has

been confusion over possible links to the country of the same name, but Sudan officials say there is no

connection whatever.

   Sudan 1 is a red industrial dye that has been found in some chilli powder, but was banned in food

products across the European Union (EU) in July 2003.

   Since the ban was put in place, EU officials have been striving to remove some food products from

the shelves. So far 580 products have been recalled.

Last week Sudan's Embassy in the United Kingdom asked the Food Standards Agency (FSA) for

clarification of the origin of the dye's name.

   Omaima Mahmoud Al Sharief, a press official at Sudan's Embassy in China, explained the purpose

of the inquiry was to clear up any misunderstanding over links between the country and the poisonous

dye.

"We want to keep an eye on every detail and avoid any misunderstanding there," she said. "Our embassy

to Britain asked them how the dye got that name and whether the dye had something to do with our

country. But they told us there was no relationship."

   The FSA, an independent food security watchdog in Britain, received a letter from the Sudanese

embassy last week.

    "They asked us why the dye is named Sudan, however, we also do not know how it got the name,"

she said. "People found the dye in 1883 and gave it the name. Nobody knows the reason, and we

cannot give any explanation before we find out."

   Sudan dyes, which include Sudan 1 to 4, are red dyes used for colouring solvents(溶剂), oils,

waxes, petrol, and shoe and floor polishes. They are classified as carcinogens by the International

Agency for Research on Cancer.

1. What does the underlined word mean in paragraph one?

A. Causing cancer.    

B. Having side effect.    

C. Containing poison.    

D. Poisonous.

2. How did the Sudan 1 get its name?

A. The dye is often produced in Sudan.

B. The dye has something to do with the country named Sudan.

C. Nobody is sure of the origin of the name.

D. Many foods produced in Sudan contain the dye.

3. We can infer from the passage that        .

A. the Sudan government is paying much attention to the food safety

B. Sudan 1 is often used to be added to the food

C. people didn't realize the danger of Sudan 1 until 2003

D. many food shops will be closed down

4. Which of the following is the best title?

A. Keep away from Sudan 1

B. No Sudan 1 dye links to the country

C. How Sudan 1 dye got its name?

D. Pay attention to the food safety