问题 填空题

亚氯酸钠(NaClO2)是一种强氧化性漂白剂,广泛用于纺织、印染和食品工业。它在碱性环境中稳定存在。某同学查阅资料后设计生产NaClO2的主要流程如下。

(1)Ⅰ、Ⅲ中发生反应的还原剂分别是                   (填化学式)。

(2)Ⅱ中反应的离子方程式是                         

(3)A的化学式是             ,装置Ⅲ中A在           极区产生。

(4)ClO2是一种高效水处理剂,可用亚氯酸钠和稀盐酸为原料制备:

5NaClO2 + 4HCl =" 5NaCl" + 4ClO2↑ + 2H2O。

① 该反应中氧化剂和还原剂的物质的量之比是                

② 研究表明:若反应开始时盐酸浓度越大,则气体产物中Cl2的含量越大,运用氧化还原反应规律分析其原因是                                      

(5)NaClO2变质可分解为NaClO3和NaCl。取等质量变质前后的NaClO2试样配成溶液,分别与足量FeSO4溶液反应时,消耗Fe2+的物质的量相同,从电子守恒的角度解释其原因是                    

答案

(1)Na2SO3  H2O(2分)

(2)2ClO2 + H2O2 + 2OH = 2ClO+ O2↑+ 2H2O(2分)

(3)H2SO4(2分)  阳 (2分) 

(4)1∶4 (2分)  ClO的氧化性或Cl的还原性随溶液的酸性和浓度的增大而增强,因此Cl被氧化得到Cl2  (2分)

(5)NaClO2变质前后分别与Fe2+反应时,最终均得到等量NaCl,Cl元素均由+3价变为-1价,根据电子守恒,两个过程中得到的电子的物质的量相同(2分)

题目分析:(1)Ⅰ中发生的反应是亚硫酸钠被氯酸钠氧化,、Ⅲ中发生的反应是电解水,因此在这两个反应中还原剂分别是:Na2SO3  H2O(2分)

(2)2ClO2 + H2O2 + 2OH = 2ClO+ O2↑+ 2H2O(2分)

(3)Ⅲ装置中左边氢氧根离子放电,剩余的氢离子跟硫酸根离子结合成硫酸,所以A是:H2SO4; 因为是氢氧根离子放电,所以这边是电解池的阳极。

(4)在这个反应中发生的是亚氯酸钠中氯元素的自身氧化还原反应,既作氧化剂,也作还原剂,作氧化剂的亚氯酸钠是化合价降低的,也就是由正三价变成正一价,为一摩尔,作还原剂的亚氯酸钠是化合价升高的,也就是由正三价变成正四价,为四摩尔,所以该反应中氧化剂和还原剂的物质的量之比是1∶4 ;ClO的氧化性或Cl的还原性随溶液的酸性和浓度的增大而增强,因此Cl被氧化得到Cl2

(5)NaClO2变质前后分别与Fe2+反应时,最终均得到等量NaCl,Cl元素均由+3价变为-1价,根据电子守恒,两个过程中得到的电子的物质的量相同(2分)

阅读理解

阅读理解

     Lucille Clifton, the AwardWinning Poet, was the First African American Poet Laureate of Maryland.

Critics call her one of the greatest writers of our time.

     Lucille Clifton was born Thelma Lucille Sayles in Depew, New York in 1936. She was named

Thelma after her mother. Lucille was the name of one of her father's ancestors. When the younger one

got older she chose to call herself Lucille.

     Lucille Clifton began writing poetry when she was about ten years old. She had developed an interest

in poetry because of her mother, Thelma Sayles. Her mother was also a poet although her poems were

never published. As a child Lucille would sit on her mother's lap and listen as she read poetry. She

learned to love words and the power of words. That stayed with her as she grew.

    While her mother taught her to love poetry, her father gave her the gift of storytelling. He would tell

Lucille interesting stories about her ancestors, especially the one named Lucille who was his grandmother. Samuel Clifton said she was the first black woman to be legally hanged in the state of Virginia. Lucille

Clifton wrote about it in her poem called "Lucy".

     She often talked about her love for words. She loved the sound of words and the way the words felt

in her mouth. She loved finding interesting ways to use words to express what was happening in the

world.

     Unlike her mother, Lucille Clifton's poetry was anything but traditional. Her poems do not rhyme or

follow a special kind of pattern. They do not use fancy words. They do not deal in makebelieve. Her

poetry is known for being simple, truthful and direct. It is written the way people speak, in a casual,

relaxed language. There is very little punctuation(标点) and even less capitalization. Many of the poems

are uncomfortably honest. Lucille Clifton often said that she tried to comfort the afflicted and afflict the

comfortable. Over the years, she seems to have perfected that art.

1. Which of the following may be the reason why Lucille Clifton chose to call herself Lucille instead of

    Thelma?

A. To show her love to her mother.

B. To show her love to her beloved teacher.

C. To show respect to her greatgrandmother.

D. To show her respect to a great poet.

2. From the passage, we know that Lucille Clifton is ________.

A. funny  

B. creative  

C. selfish  

D. beautiful

3. What is the main idea of the last paragraph?

A. Lucille Clifton's great works.

B. Lucille Clifton's poem background.

C. Lucille Clifton's poem style.

D. Lucille Clifton's poem words.

4. The underlined word "it" in the fourth paragraph probably refers to ________.

A. Samuel Clifton

B. Samuel Clifton's experience

C. Samuel Clifton's grandmother

D. Lucille's great grandmother's story

判断题