问题 选择题

NA为阿伏加德罗常数,下列有关说法正确的是(  )

A.1molNa2O2与水完全反应,转移电子数为NA

B.胆矾、冰醋酸、硫酸钡和聚乙烯均为电解质

C.标准状况下,等物质的量的SO2和SO3所占体积相同

D.配溶液所用的容量瓶必须检查是否漏水,中和滴定中所用的锥形瓶必须用待装溶液润洗

答案

A、过氧化钠与水反应,过氧化钠起氧化剂与还原剂作用,各占

1
2
,起氧化剂作用过氧化钠,氧元素由-1价升高为0价,所以1molNa2O2与水完全反应,转移电子数为NA,故A正确.

B、聚乙烯不溶于水且熔融状态下也不导电,所以属于非电解质,故B错误.

C、标况下,三氧化硫是固体,气体摩尔体积对其不适用,导致无法计算其体积,故C错误.

D、中和滴定中所用的锥形瓶用待测溶液润洗,会导致消耗的标准液体积增大,计算所测溶液的物质的量浓度偏大,故D错误.

故选A.

单项选择题
阅读理解

阅读理解。

     The early 1900s were very different from today.Toys,though they have evolved in many ways,were

still the delight of children everywhere.

      Theodore Roosevelt's Presidency marks the beginning of the "Teddy Bear". In the year 1902,toy

bears were named "Teddy" after the president's nickname.The Teddy Bear became known worldwide

,and is still known and loved today.It was only a few years later that the Teddy Bears were mass produced.

      In 1913,an item called the Erector Set was invented.It was a steel,motorized toy that children could

use to build models of anything.Its creator was A.C.Gilbert,a medical doctor.

      Charles Pajeau created a similar wooden set called Tinker Toys in the year 1914.Tinker Toys were

made for younger children.

      Raggedy Ann dolls first came on the scene after newspaper cartoonist Johnny Gruelle reproduced

the doll he made for his daughter.That was in 1915.

      The following year,an architect's son named John Lloyd Wright,invented Lincoln Logs,which were

interlocked to make structures.

      Two years after Mickey Mouse was created,stuffed(填塞)Mickey Mouse dolls were made by

Charlotte Clark.This was the start of Disney merchandise.

      The yoyo became popular in the United States after Donald Duncan bought a yoyo company in 1929.

      The ViewMaster,a three dimensional viewer,was developed by a camera enthusiast named William

Gruber.The toy became popular when Gruber licensed Disney characters to make still,3D images from

Disney movies and television programs.

      Finally,in 1940,model airplanes were mass produced.They started out as a way for manufacturers to

sell planes to the military,but later caught on as a toy.

      The toys that we know and love today have had their roots from these ancient times.Isn't it interesting

to know that if it hadn't been for all these creative people,most of the games you know today would never have been?

1.Why were toy bears named "Teddy"?

A.To be suitable for mass production.

B.To be easily pronounced by children.

C.To meet the advertisers' needs.

D.To memorize President Theodore Roosevelt.

2.In which aspect do the toys created by Gilbert differ from those by Charles?

A.Shape.  

B.Material used.

C.Themes.  

D.Price.

3.When did the ViewMaster become popular?

A.After William Gruber was born.

B.After Gruber licensed Disney characters.

C.Two years after Mickey Mouse was created.

D.When Disney merchandise was started.

4.From the last paragraph we can learn that________.

A.those people who created these games should never be forgotten

B.some toys created in ancient times now disappear

C.creativity exists in every field all the time

D.toys nowadays are totally different from those in ancient times

5.What does the passage talk about?

A.The function of toys.

B.The history of Disney characters.

C.Toys in the early 1900s.

D.The financial meaning of toys.