问题 实验题

(10分)有一瓶浅绿色的硫酸亚铁晶体,由于保存不善,导致它在空气中敞口放置了较长的时间,因此该晶体可能被氧化。试用实验证明它是未被氧化或部分被氧化还是全部被氧化,并完成实验报告。

(1)实验目的:                 

(2)实验步骤:

①取少量该晶体溶于水,加酸酸化;

②将溶液分成两份,并置于洁净的试管中,向其中一份溶液中滴加几滴KSCN溶液;

③向另一份溶液中滴加少量的KMnO4溶液。

(2)第①步用酸酸化可以用下列的酸是  

A.稀硝酸

B.盐酸

C.浓硫酸

D.稀硫酸(3)结论:

                 ,则说明部分被氧化。

                ,则说明全部被氧化。

③写出硫酸亚铁溶液在酸性条件被氧化的离子反应方程式         。

答案

(10分)

(1)证明硫酸亚铁晶体未被氧化或部分被氧化还是全部被氧化。(2分)

(2) D(2分)

(3) ①:②中反应后溶液变红色;③中反应后溶液颜色变浅或褪去。(2分)

②:②中反应后溶液变红色;③中溶液不变色。(2分)

③:4Fe2+O2+4H===4Fe3+2H2O(2分)

考查铁离子的检验

(1)证明硫酸亚铁晶体未被氧化或部分被氧化还是全部被氧化

(2)为防止Fe2被氧化,不能用强氧化性酸,排除AC;由③知道,用KMnO4溶液来检验Fe2的存在,而KMnO4溶液在常温下可被盐酸还原,使其褪色,干扰了Fe2的检验,排除B;故答案为D:加酸可防止Fe2、Fe2的水解

(3)加入KSCN溶液溶液呈红色,则说明含有Fe3,如果KMnO4溶液褪色,则说明含有Fe2;故

①:②中反应后溶液变红色;③中反应后溶液颜色变浅或褪去说明部分被氧化

②:②中反应后溶液变红色;③中溶液不变色,则说明全部被氧化

③:由化合价升降守恒及电荷守恒可配平此离子方程式:4Fe2+O2+4H===4Fe3+2H2O

阅读理解

Wu You, a 14–year–old Chinese Australian, used her diary to record what she had experienced in Guangzhou during this year’s Spring Festival travel period.

She, like tens of thousands of passengers stranded (滞留) at the Guangzhou Railway Station, had a Spring Festival she could never forget. But different from most people, she put down what she saw and heard in her diary, which was published in Australia.

Born in Sydney, Australia, Wu You’s grandfather and parents are professional painters, and she started to write diaries with pictures when she was only ten years old. She never expected to become famous because of her diary describing her life in Guangzhou.

“We originally planned to stay for half a month in Guangzhou when we arrived in January,” said Huang Qin, Wu’s mother. But the snowstorm caused the breakdown of traffic and kept the family there. “This is her first Spring Festival in China and probably the most special one,” said Huang. “We watched TV news programs every day and prayed for the snowstorm to be over soon so that stranded passengers could go home as soon as possible.”

Then Wu You started writing diaries about the snowstorm and the stranded passengers, along with the traditional customs in Guangzhou as well as local attractions such as the flower fair.

“In her diary she just wrote down what she heard and saw every day, and with her pencil she added some illustration to every diary. When we went back to Australia, people saw the diaries and asked to publish them on a local newspaper,” said Huang, “because they thought the diaries are very heart – warming.” All of Wu You’s diaries were written in English, and translated into Chinese by her mother. Through her diary, the girl shows her care to the Chinese people. In one diary, she wrote, “I really hope the warmth from people’s love can melt the cold snow and ice.”

72. Wu You wrote diaries during her stay in Guangzhou because she _______ .

A. has the habit of keeping a diary                 B. wished to make her name known

C. needed a means to kill time                    D. experienced so many interesting things

73. We can infer from the story that Wu You _____ during the Spring Festival.

A. did nothing besides watching TV and writing diaries 

B. helped clear away the snow and ice

C. helped other stranded passengers in difficulty  

D. had activities to get a taste of the local culture

74. The underlined word “illustration” in the last paragraph refers to _______.

A. photos             B. drawings         C. translations           D. tips

75. Her diary is believed worth publishing mainly because it tells about the ______.

A. wonderful places in Guangzhou covered in ice and snow

B. interesting ways of locals observing the Spring Festival

C. severe disaster caused by the snowstorm

D. moving stories of the passengers being helped

单项选择题