问题 选择题

NA表示阿伏加德罗常数,下列叙述正确的是(  )

A.12gC-12中含有的电子数为12NA

B.46gNO2和46gN2O4含有的原子数均为NA

C.1.7gH2O2中含有的电子数为0.9NA

D.标准状况下,2.24L乙醇所含分子数为0.1NA

答案

A、12gC-12的物质的量为1mol,含有6mol电子,含有的电子数为6NA个,故A错误;

B、NO2和N2O4的最简式为NO2,46g NO2和46g N2O4含有1mol最简式NO2,都含有3mol原子,含有的原子数均为3NA,故B错误;

C、17g双氧水的物质的量为0.05mol,0.05mol双氧水中含有0.9mol电子,含有的电子数为0.9 NA,故C正确;

D、在标准状况下,乙醇为液体,不能使用标况下的气体摩尔体积计算2.24L乙醇的物质的量,故D错误;

故选C.

阅读理解

阅读理解。

     Pop singer star Britney Spears would feel happy (or amused) if she knew what her songs can do for some

German farmers.

     Recently, some farmers in Germany have been playing Britney's songs very often on their farms. Not that

they like her songs a lot, but that her songs can drive away the troublesome wild boars (野猪)!

     As the boars are an endangered animal in Germany, people can't shoot or kill them. Farmers there tried their

best to stop the boars from destroying their crops but failed.

     One day, one of the German farmers noticed that all the boars were scared away when he started to play

one of Britney's songs!

     The farmer was delighted and then he tried some other singers on the boars. Madonna's and Robbie

Williams' songs didn't work at all.

     Only Britney's songs seemed to have the magical power. Every time her songs were played on his farm, the

boars would go running away in a rush.

     It's reported quite a number of German farmers are using Britney's magic songs to protect their vegetable

and fruits.

1. The farmers play Britney's songs on their farms so that _____. [ ]

A. they can protect their crops and fruits

B. they don't feel tired from working

C. their crops may grow better

D. they can get some money from the music company

2. The farmers cannot shoot the boars because _____. [ ]

A. they are not allowed to own guns

B. they are afraid the boars might attack them

C. the boars are protected by law

D. the boars are owned by some other farmers

3. Which of the following statements is true ac-cording to the text? [ ]

A. Animals like to listen to music by different singers.

B. Not all the singers' songs are liked by the boars in Germany.

C. Boars in Germany like Britney's songs very much.

D. Britney's songs seem to be quite different from other singers'.

单项选择题