问题 实验题

某化学小组将CaCO3与HCl反应后的废物进行处理,目的是制取中性干燥剂CaCl2.经过处理得到固体后,他们对得到的固体成分进行猜想:

【猜想】

猜想一:固体中只有CaCl2

猜想二:固体中既有CaCl2,又有CaCO3

猜想三:固体中只有CaCO3

为了验证猜想,他们进行实验探究,请你帮助他们完成以下实验报告。

【实验】

 实验设计图示操作步骤实验现象实验结论
步骤一               上层液体澄清,试管底部仍然有少量固体。猜想     不成立(选填“一”、“二”、或“三”)
步骤二                

上层清液加入AgNO3溶液后有白色沉淀。

 

猜想      不成立(选填“一”、“二”、或“三”)

步骤三 

取少量步骤一未溶固体于试管中,滴入        

(填写物质名称或化学式)

 

            

 

猜想      成立(选填“一”、“二”、或“三”)

答案

 实验设计图示操作步骤实验现象实验结论
步骤一取少量样品于试管中,加入足量的水,振荡上层液体澄清,试管底部仍然有少量固体.猜想不成立(选填“一”、“二”、或“三”)
步骤二 

取少量上层清液于试管中,滴入AgNO3溶液

 

上层清液加入AgNO3溶液后有白色沉淀.

 

猜想不成立(选填“一”、“二”、或“三”)

步骤三 

取少量步骤一未溶固体于试管中,滴入HCl

(填写物质名称或化学式)

 

有大量气泡

 

猜想成立(选填“一”、“二”、或“三”)

 

题目分析:根据题干提供的信息进行分析,碳酸钙不溶于水,且碳酸钙能与酸反应生成二氧化碳气体,检验氯化钙的存在可以使用加入硝酸银溶液的方法,氯化钙能与硝酸银反应生成氯化银沉淀,据此解答即可。

步骤一出现的现象是试管底部有少量固体,说明不能只是氯化钙存在,猜想一不成立;

步骤二中在上层清液加入硝酸银溶液后有白色沉淀,说明含有氯化钙,故猜想三不成立;

步骤三中在未溶解的固体中加入盐酸有气泡产生,说明含有碳酸钙,故猜想二成立;

单项选择题
阅读理解

IV.阅读理解(共20小题;每小题2分,满分40分)

  阅读下列短文,从每题所给的四个选项(A,B,C和D)中,选出最佳选项。

  With her beautiful looks, cheerful character and strong spirit, Karena Lam(林嘉欣)is making waves among Chinese movie fans and professionals (专业人士).

  The Canada - born actress won the Golden Horse Best Supporting Actress and Best New Performer awards (金马奖最佳女配角和最佳新人奖)for her role in “July Rhapsody” (《男人四十》)in Taiwan on November 16.She won the same titles at the HongKong Film Awards in April, 2002.

  Lam played a wifful (任性的)high school girl in the film and her idol (偶像)Jacky Cheung (张学友)played the girl 's middle - aged teacher.

  Her awards have made her the person to watch in Hong Kong and Taiwan cinema. But the 24-year-old girl thinks the awards have put more pressure on her and given her new challenges (挑战).

  Besides Jacky Cheung, Lam has appeared alongside other top Hong Kong stars. Last year she starred with Leslie Cheung (张国荣)in“ Inner Senses ” (《异度空间》)and this year she acted with Nicholas Tse (谢霆锋)in“ Tiramisu” (《恋爱行星》). Is there anything that can stop Lam's success?

  “I have learnt that ff someone is trying to hurt you, the best revenge (报复)is to keep living happily and having a good life.That’s what I did, ” she said.

  She is an optimist (乐天派)and determined to be successful. “I always have a way of finding my own happiness. I know what's going to make me smile, and I go for it, ”she said.

  Two films—a comedy and a love - story are waiting for her and she plans to release (首次上演)her first Cantonese (粤语)album next summer.

41.According to the passage, which of the following shows the right order of what Lam did or will do?

  a.To star with Leslie Cheung in“Inner Senses.”

  b.To win the Golden Horse Best Supporting Actress and Best New Performer awards for her role in“ July Rhapsody.”

  c.To release her first cantones album.

  d.To act with Nicholas Tse in“ Tiramisu. ”

  e.To win the Hong Kong Film Awards.

  A. b, e, a, d, c   B. c, a, d, e, b     C. e, b, d, c, a   D. a, d, e, b, c

 42.In“Inner Senses” Lam was one of the________performers.

  A. supporting  B. chief      C. ordinary   D. learned

 43.The underlined phrase“make waves” probably means________.

  A. gain much attention   B. make trouble

  C. sing and dance    D. fan the flames of disorder