问题 填空题

根据如图实验装置图,按要求回答有关问题:

(1)写出图中带有标号仪器的名称:a      ;b             

(2)在实验室中用高锰酸钾制取氧气时,所发生的化学反应方程式为                      

(3)实验室制取二氧化碳气体,应选择的发生装置为     (填写装置的字母代号,下同);应选用的收集装置是        。检验二氧化碳是否收集满的方法是:将燃着的木条放在      ,观察火焰是否熄灭.二氧化碳溶于水的化学方程式为                             

(4)下列是初中化学部分重要的实验或实验装置。

①A实验右边玻璃管②中产生的气体是                                   

②B实验如果实验数据小于21%,可能原因是                                   (写出一点);

③C实验蜡烛火焰熄灭说明二氧化碳具有的性质是                                     

答案

(1)试管;长颈漏斗; (2)2KMnO4 K2MnO4 +MnO2 +O2↑;

(3)B;  E;集气瓶口;CO2 +H2O=H2CO3

(4))①氢气(或H2);  ②装置漏气(或加热时间短,反应不充分;或铜的量太少,氧气没完全反应;或未冷却至室温就读数等);

题目分析:(1)标号仪器分别是试管和长颈漏斗;

(2)加热高锰酸钾生成锰酸钾、二氧化锰和氧气,方程式是:2KMnO4 K2MnO4 +MnO2 +O2↑;

(3)依据制取二氧化碳的反应物的状态、反应条件选择发生装置,依据二氧化碳的密度和溶解性选择收集装置,验满时应将燃着的木条放于集气瓶口,观察木条是否熄灭。实验室制取二氧化碳用大理石和稀盐酸常温反应,属于固液常温型,故选发生装置B;二氧化碳的密度比空气大且能溶于水,故最好用向上排空气法收集; 验满时应将燃着的木条放于集气瓶口,观察木条是否熄灭;二氧化碳溶于水的化学方程式为 CO2 +H2O=H2CO3

(4)①依据电解水时生成的氢气与氧气的体积大小分析即可。电解水时生成的氢气与氧气的体积比是2:1,所以②中产生的气体是氢气;

②从测定空气中氧气的含量较实际值偏低的原因可能是:装置漏气或加热时间短,反应不充分;或铜的量太少,氧气没完全反应;或未冷却至室温就读数等;

③从二氧化碳能使火焰熄灭分析判断。石灰石可以与盐酸反应生成二氧化碳,蜡烛火焰熄灭说明二氧化碳不能燃烧,不支持燃烧。

完形填空

III.  Reading Comprehension

Section A

Directions: For each blank in the following passages there are four words or phrases marked A, B, C and D. Fill in each blank with the word or phrase that best fits the context.

People with a positive attitude toward aging can adjust very well when individual circumstances change. Their positive outlook allows them to   50   to the inevitable physical and biochemical changes of the body that are associated with the natural   51   of aging. With a healthy outlook on the golden years, even unpredictable setbacks and disabilities can be managed   52  .

Individual genetic makeup (基因构造) explains the great   53   in the aging rate. Some seniors experience more challenges than others of the same age, and some seniors continue to function better than many younger people. But genetics only   54   about 30 percent of aging. Most of the changes we associate with age   55   factors such as diet and exercise habits; lifestyle issues, including over   56   of alcohol and tobacco, and psychological traits.

We can make healthy lifestyle choices by staying   57   both physically and mentally and by   58   a healthy diet. Some of the setbacks associated with advancing age such as   59   eyesight, loss of hearing, forgetfulness, weakness can be forestalled with some active intervention(干预).

Growing older does not always mean you see poorly. Many older people have   60   good eyesight well into their eighties and beyond. However, the single greatest contributor to vision loss is a lifetime of   61   to damaging ultraviolet (紫外线) radiation in sunlight.

Carotenoids(类胡萝卜素), a nutrient found in brightly colored vegetables and fruits, are powerful protectors against free-radical damage. Research shows that simply eating leafy greens and other foods rich in these protective nutrients can   62   vision loss.

Problems with hearing can create   63   and insecurity in later years. One of the major causes of age-related hearing loss is damage to the hair cells in the inner ear that transmit sounds to the brain. These hair cells and their nerve endings can be damaged by infections, genetic diseases, or treatment with certain drugs. The most common cause,   64  , is loud noise.

50.   A. stick                B. devote               C. adapt                D. lead

51.   A. progress            B. process              C. program            D. project

52.   A. successfully       B. purposefully      C. unwillingly        D. carefully

53.   A. surprise             B. variation           C. increase             D. possibility

54.   A. relies on            B. accounts for       C. results from              D. lies in

55.   A. involve in         B. relate to            C. combine with     D. substitute for

56.   A. reputation         B. enjoyment               C. consumption      D. encouragement

57.   A. active               B. calm                 C. efficient            D. diligent

58.   A. maintaining              B. feeding             C. surviving           D. controlling

59.   A. keen                B. failing               C. sharp                D. remote

60.   A. generally           B. frequently         C. relatively           D. occasionally

61.   A. contribution      B. introduction       C. explanation        D. exposure

62.   A. cure                  B. relieve                     C. reduce               D. suffer

63.   A. communication  B. isolation            C. competition              D. occupation

64.   A. therefore           B. otherwise          C. moreover          D. however

单项选择题