问题 填空题

用固体NaOH配制100 mL 0.1 mol·L-1的NaOH溶液,在天平上称出_________g NaOH放在烧杯里,用适量的蒸馏水使之完全溶解。把所得的溶液通过___________小心地注入100 mL容量瓶中,然后用蒸馏水______,把每次洗下来的水都注入__________。振荡容量瓶里的溶液,使之混合均匀。缓慢地把蒸馏水注入容量瓶直到______,然后改用_______滴加蒸馏水,使溶液的凹面_________,最后把容量瓶塞塞好,即配制成0.1 mol·L-1的NaOH溶液。在使用容量瓶前,用蒸馏水洗净后_____________,(填“需要”或“不需要”)将容量瓶进行干燥。在配制溶液过程中,两次用到小烧杯,其作用分别是________和_________;两次用到玻璃棒,其作用分别是___________和____________。

如果出现下列情况,会使溶液物质的量浓度如何变化?(填“偏高”“偏低”或“不变”)。

(1)所用NaOH已潮解,则结果________________________________。

(2)向容量瓶中加蒸馏水,未到刻度线,则结果___________________________。

(3)向容量瓶中加蒸馏水,超过刻度线,则结果_______________________________。

(4)小烧杯、玻璃棒没洗涤,则结果­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­________________________________。

(5)观察刻度线时仰视,则结果________________________________。

(6)所用容量瓶中,已有少量蒸馏水,则结果________________________________。

(7)称量的是长期暴露在空气中的NaOH,则结果________________________________。

答案

0.4 玻璃棒洗涤烧杯和玻璃棒2~3次容量瓶中液面距离容量瓶刻度线1~2 cm的位置胶头滴管正好与刻度线相切,反复摇匀不需要称量时用于盛装腐蚀性药品NaOH 用于溶解 NaOH溶解时搅拌加速溶解移液时引流用

(1)偏低(2)偏高(3)偏低(4)偏低(5)偏低(6)不变(7)偏低

本题主要考查了配制一定物质的量浓度的溶液的基本操作及误差分析,要求学生熟悉仪器的使用,掌握实验操作中应注意的问题,对实验过程中可能出现的误差要有全面的认识。

名词解释
阅读理解

Now let’s compare the Chinese diet with the Western diet. Some say that the Western food is better than the Chinese food. Do you think so?

First, let’s make a standard(标准) of the better diet. We don’t have to care much about the shape, the colour and the taste of the food. We say the one that has more nutrition, is easier to be digested and absorbed(吸收) by the body and then makes us more energetic should be the better. In this way, I believe, our Chinese food should be better than the Western food. Why?

I think the Western food contains too much fat and sugar. I know both fat and sugar are a kind of nutrition we need in our body, but too much of them will make your body harmed. That’s why so many westerners get ill when young. Besides, westerners have to use knives, forks and spoons to help them have their meals. It seems that they couldn’t have their meals without force.

But in Chinese food we have those mainly from plants including their seeds, leaves and roots together with a little meat such as chicken, fish, pork, mutton and so on. With so much plant food we can get enough calories as it is rich in fiber, protein, calcium and fat. With a little meat we can make our body even stronger. Besides, we use chopsticks, bowls and plates to help us have our meals. All of these make us harmonious to nature and everybody around us. So I say our Chinese food makes us wise, happy, healthy and wealthy.

1. What is the passage mainly about?

A. The taste of the Chinese food.

B. The taste of the Western food.  

C. The comparison between the two kinds of food.     

D. The tastes of both of the two kinds of foods.

2. Which is the standard of measuring a diet?

A. Quantity of nutrition in the food.

B. Whether it is easy to be digested and absorbed.

C. Whether it can offer us enough energy.      

D. All of the above.

3. Which is the writer’s attitude towards diet according to the passage?

A. Western food should be better because it contains much fat and sugar.

B. Western food should be better because contains much calories.

C. Chinese food should be better because it doesn’t contain too much fat or sugar

D. Chinese food should be better because it doesn’t have much nutrition.

4. According to the passage, which statement is true?

A. The standard (标准) of a better diet depends on the shape, color and the taste of the food.

B. Fat and sugar in the food do harm to our body.

C. Westerners use knives, chopsticks and spoons to help them have meals while Chinese use bowls, forks and plates.

D. Chinese food and the way Chinese have meals show Chinese are more harmonious with nature.