问题 问答题

请阅读下面酸碱中和滴定案例片段,回答下列问题

教师活动 学生活动
课堂
引入
[引入]人们常用离子的特征反应来检验一些常见离子,例
如:可以利用Fe3+与SCN-反应生成血红色溶液这一性质来
检验Fe3+。像这样只检验种类,不测定含量的分析方法,化
学上称为定性分析。
有时,我们还需要测定某些物质或元素的含量,这就需要用
到另一种分析方法——定量分析。今天,我们来学习一种
重要的定量分析方法——酸碱中和滴定。
概念及
原理
介绍
[板书]酸碱中和滴定
1.定义:用已知物质的量浓度的酸(或碱)来测定未知物质
的量浓度的碱(或酸)的方法。
2.原理:酸碱中和反应实质 (a) (用离子方程式表示)
则:n(H+)=n(OH-)
即:c(H+)×V(H+)=c(OH-)×V(OH-)
听讲、记好笔记
认识滴
定管和
指示剂
[过渡]酸碱中和滴定在理论上是简单清晰的。但在具体的
实践操作中,还有两个关键需要克服。A.准确测定参加反应
的两种溶液的体积:B.准确判断中和反应恰好进行完全(找
到完全中和点)。下面就一起学习如何解决理论到实践中
出现的问题。
[讲评]解决办法
A.准确测定参加反应的两种溶液的体积:使用滴定管(展示
滴定管,放在滴定管夹上)
[互动1]请大家观察自己桌上的滴定管,并试着说明它的结
构特点。
[讲解]
酸式滴定管:盛放酸性溶液,不能盛放碱性溶液。
(因为 (b) )
碱式滴定管:盛放碱性溶液,不能盛放酸性溶液和强氧化性
溶液。(因为橡皮管容易被腐蚀,结构决定适用范围)
[互动2]为什么酸碱中和滴定中测定溶液的体积不用已有
的量筒,而选用滴定管
(评讲中可与量筒对比说明,并演示滴定管用于精确的测量
放出的液体的体积。)
B.准确判断中和反应恰好进行完全——选用合适指示剂。
(指导阅读材料)
[互动1]学生观察讨论,举手发言,并最
后总结:
1)内径均匀、带有刻度的细长玻璃管:
0刻度在上、从上往下分布刻度、最大量
程下端有一段无刻度。
2)滴定管上标有参数——温度、最大量
程。
3)下端有控制液流的活塞(一种是普通
玻璃活塞、另一种是橡皮管和玻璃球组
合的阀)
[互动2]精确度更高、能精确到 (c) ;便
于控制液流。
[互动3]学生阅读后总结:
1)变色点尽量接近完全中和点时溶液的
pH;
2)变色要灵敏、明显;
3)……
认识滴
定管和
指示剂
[互动3]既然指示剂的选择直接关系到酸或碱的用量,因
此,必须是最合适的指示剂。如何选择指示剂呢
[板书]选择指示剂的原因:一般是 (d)
[说明]决不用石蕊(颜色不易辨别,且变色范围过大)
强酸——强碱:……
强酸——弱碱:……
弱酸——强碱:……
演示实
验操作
[过渡]下面以0.1000mol/L HCl溶液滴定NaOH溶液为例,
讲解中和滴定实验的操作步骤和注意事项。
学生听讲并留心观察

该片段中的教学重点是______,完成这一内容的教学采用最主要的教学方法是______。

答案

参考答案:①活动探究酸碱中和反应的原理和生活应用
②观察法、讨论法

填空题
阅读理解

The Chinese word “Shanzhai” means a small mountain village, but now it becomes an accepted name for fakes (假货) after “Shenzhen Cellphones” produced by small workshops in southern China became popular in the mainland market over the past two years.

Besides “Shanzhai” has electronic products, there are “Shanzhai” movies, “Shanzhai” stars and even a “Shanzhai” Spring Festival Gala, a copy of the 25-year-old traditional show presented by CCTV on Chinese Lunar New Year’s Eve.

“Shanzhai” has become a culture of its own, symbolizing anything that imitates something famous.

The phenomenon has caused a public debate over whether it is healthy or sick being a copycat.

In southwestern China’s Chongqing Municipality, a “Shanzhai” version “Bird’s Nest” woven by farmers with bamboo attracts wide attention and the “Shanzhai” version “Water Cube” is popular with tourists too. Both are copies of the famous Olympics buildings in Beijing.

Xie Xizhang, a literature critic, said that taking the “Shanzhai” Gala as an example, when the traditional CCTV program becomes less and less attractive to the audience, the “Shanzhai” version appears naturally to attract people.

“In spite of its poor techniques and operation, ‘Shanzhai’culture meets the psychological demands of common people and could be a comfort to their minds,” Xie said.

Tian Huiqun, a professor at Beijing Normal University, said that “Shanzhai” culture never copies classic things, only trendy products. In that sense, it’s like a computer virus, multiplying without meaning.

Though controversial, “Shanzhai” culture is becoming a widely accepted phenomenon.

To the mainstream culture, the rise of “Shanzhai” culture is a challenge as well as a motivation, said Xie.

Tian said different kinds of cultures developing together is an ideal situation and it is for the public to choose.

1. The Chinese Word“Shanzhai”may have its origin in _________.

A. fake cellphones          B. electronic products 

C. Spring Festival Gala     D. Olympics buildings

2. A. The underlined word “imitates” is closest in meaning to _______.

A. steals     B. copies     C. advertises    D. cheats

3. A. According to the passage, “Shanzhai” culture refers to ________.

A. The action that a person imitates famous people

B. anything that imitates something famous

C. those similar names to famous brand

D. products with poor techniques and quality

4. A. We can infer that the mainstream culture ________.

A. Will be held back by “Shanzhai” culture

B. will sooner or later be replaced by “Shanzhai”culture

C. may develop faster because of the challenging of “Shanzhai”culture

D. thinks nothing of the challenge of “Shanzhai”culture

5. Which of the following might be the best title of passage?

A.“Shanzhai”culture will definitely fade out

B.“Shanzhai”culture –the mountain village culture

C.“Shanzhai”culture – the mainstream culture

D.“Shanzhai”culture takes on life of its own