问题 选择题

分子式为C4H9Br的有机物的可能结构有

A.2种

B.3种

C.4种

D.5种

答案

答案:C

专题:同分异构体的类型及其判定.

分析:化学上,同分异构体是一种有相同化学式,有同样的化学键而有不同的原子排列的化合物.简单地说,化合物具有相同分子式,但具有不同结构的现象,叫做同分异构现象;具有相同分子式而结构不同的化合物互为同分异构体.

解答:分子式为C4H9Br从饱和度看只能是饱和溴代烷烃,同分异构只是溴在碳上面链接位置不同而已,因为丁烷有两种同分异构体,它们一溴代物的种数即为C4H9Br的种数,正丁烷两种一溴代物,异丁烷两种一溴代物,共4种,所以分子式为C4H9Br的同分异构体共有4种.故选C.

点评:本题考查学生同分异构体的概念和应用知识,可以根据所学知识来回答,难度不大.

单项选择题 B1型题
阅读理解

Intellectual property (IP) is a product of the mind that has commercial value. The concept dates back to 1623, when the first patent law to protect IP rights was passed. IP rights protect an artist from having his/her creative ideas copied by another. For example, if somebody generated an idea for a novel, that idea is protected by IP rights. If someone else wishes to represent the idea or develop it further, he/she must consult the original artists, who will normally be rewarded financially for its use. Back in the 17th century, IP rights were primarily carried out to protect newly developed manufacturing processes against stealing, but today intellectual property rights are also enjoyed by those who create music, art and literature.

In recent years, IP rights have been the focus of a great deal of discussion because of a technology which looks set to weaken them altogether: the Internet. Many years ago, if you wanted a recoding of a song, you would have to purchase it from a music store; if a novel, from a book store. In those days, IP rights were easily protected since it was very difficult to obtain intellectual property without paying for it. However, a lot of IP, including songs, films, books and artwork, can be downloaded today free of charge using the internet. This practice has now taken the world by storm, dramatically affecting the way in which we view IP rights.

小题1:According to the writer, in the beginning, IP rights were mainly of use to _______.

A.those creating music, art and literature

B.novelists

C.those not receiving financial reward for their work

D.engineers and inventors小题2:What do we know about the Internet according to the passage?

A.It does not affect the way we understand IP rights.

B.It sells songs and films.

C.It makes IP rights harder to protect.

D.It prevents the production of artwork.小题3:According to paragraph 2, what has “taken the world by storm”?

A.Intellectual property rights.

B.Free downloading.

C.The Internet.

D.The large number of songs, films and books.小题4:A possible title for this passage could be _______.

A.IP Rights and Our Attitudes 

B.Ways to Protect Your IP Rights

C.The Present and the Future of IP rights

D.A History of IP Rights