问题 填空题

从右图中,可以获得多项与甲、乙两物质溶解度有关的信息:

(1)在t2℃时,向50mL水中加入18g甲物质,充分溶解后可得到溶液      g,是          (选填“饱和”或“不饱和”)溶液;

(2)如甲物质中混有少量乙,可以用              方法提纯;

(3)两曲线的交点A表示                                  

(4)你还能获得的一项信息是:                             

答案

⑴ 65 饱和   ⑵冷却热饱和溶液 (或降温结晶)  

⑶ t1℃时,甲、乙两物质的溶解度相等。  

⑷ 甲物质的溶解度受温度变化影响较大。

题目分析:根据固体物质的溶解度曲线分析。

(1)由溶解度曲线图可知,t2℃时甲物质的溶解度为30g,故在t2℃时,向50mL水(由于水的密度为1g/ml,故相当于50g)中加入18g甲物质,充分溶解后,只能溶解15g,故可得到溶液质量为65g,由于仍有3g甲物质未溶解,故所得溶液为饱和溶液。

(2)由溶解度曲线图可知,甲、乙两物质的溶解度都随温度的升高而增大,且甲的溶解度受温度变化的影响较大,乙的溶解度受温度变化的影响不大,故要提纯混有少量乙物质的甲物质,可用冷却热饱和溶液的方法。

(3)由溶解度曲线图可知,t1℃时甲、乙两物质的溶解度曲线相交于A点,故说明t1℃时,甲、乙两物质的溶解度相等。

(4)根据固体物质的溶解度曲线,可以查出某温度下某物质的溶解度、可以比较不同的物质在同一温度下的溶解度的大小、可以判断固体物质的溶解度受温度影响变化的趋势等。

点评:本题主要考查了固体溶解度曲线所表示的意义,及根据固体溶解度曲线来解决相关问题,注重培养学生的分析问题、解决问题的能力,解题的关键是要熟记和理解固体溶解度曲线及其应用。

阅读理解

In an ideal world, people would not test medicines on animals. Such experiments are stressful and sometimes painful for animals, and expensive and time–consuming for people. Yet animal experimentation is still needed to help bridge vast gaps in medical knowledge. That is why there are some 50 to 100 million animals used in research around the world each year.

Europe, on the whole, has the world’s most restrictive laws on animal experiments. Even so, its scientists use some 12 million animals a year, most of them mice and rats, for medical research. Official statistics show that just 1.1 million animals are used in research in America each year. But that is misleading. The American authorities do not think mice and rats are worth counting and, as these are the most common laboratory animals, the true figure is much higher. Japan and China have even less comprehensive data than America.

Now Europe is reforming the rules governing animal experiments by restricting the number of animals used in labs. Alternatives to animal testing, such as using human tissue or computer models, are now strongly recommended. In addition, sharing all research results freely should help to reduce the number of animals for scientific use. At present, scientists often share only the results of successful experiments. If their findings do not fit the hypothesis being tested, the work never sees the light of day. This practice means wasting time, money, and animals’ lives in endlessly repeating the failed experiments.

Animal experimentation has taught humanity a great deal and saved countless lives. It needs to continue, even if that means animals sometimes suffer. Europe’s new measures should eventually both reduce the number of animals used in experiments and improve the way in which scientific research is conducted.

小题1:What is the main idea of this passage?

A.The success of animal experiments should be ensured.

B.A ban on the use of animals in the lab should be enforced.

C.Greater efforts need to be taken to reduce the number of lab animals.

D.Scientists should be required to share their research results with each other.小题2:Which of the following statements is true about animals used in the lab?

A.America uses only about 1.1 million lab animals per year.

B.Europe does not use mice and rats as lab animals at all.

C.Britain does not use as many lab animals as China does.

D.Japan has less comprehensive data on the number of lab animals used each year.小题3:Which of the following is mentioned as an alternative to replace animal experiments?

A.Statistical studies.

B.Computer models.

C.DNA planted in animals.

D.Tissue from dead animals.小题4:What usually happens to unsuccessful animal experiments?

A.They are not revealed to the public.

B.They are made into teaching materials.

C.They are collected for future publication.

D.They are not removed from the research topic list.

单项选择题