问题 选择题

设NA为阿伏加德罗常数的值。下列叙述正确的是

A.标准状况下,11.2L正丁烷所含共用电子对数为7NA

B.常温常压下,5.6g乙烯与丁烯的混合物中含有氢原子的数目为0.8NA

C.在50g质量分数为56%的乙醇水溶液中,含有氢原子总数为3NA

D.将CO2通过Na2O2使其增重a g时,反应中转移电子数为

答案

答案:B

题目分析:标准状况下,11.2L正丁烷所含共用电子对数为5.5NA,A错误;乙烯和丁烯的最简式为CH2,5.6g烯烃含有0.4mol最简式CH2,则0.4mol最简式CH2含有氢原子的数目为0.8NA,B正确;在50g质量分数为56%的乙醇水溶液中,含有氢原子总数应该是乙醇含有的氢原子数加上水分子含有的氢原子数,所以应大于3NA,C错误;

2Na2O2+2CO2=2Na2CO3+O2固体质量差△m  

2mol                         56g  

Xmol                          a g   

X= mol,1molNa2O2反应转移1mol电子,所以反应中转移电子数为,D错误。

阅读理解

阅读理解。

     Greenland is the largest island in the world. It covers over 2 ,000,000 square kilometers. Most of

the island lies inside the Arctic Circle (北极圈), and a huge sheet (片) of Ice covers 85% of its area.

     Along the sea mountains rise from the sea. There are a few low trees in the southwest, but no forests.

In winter snow covers everything, but in summer very low plants cover the ground between the sea and

the Ice sheet. Norwegians (挪威) were the first Europeans to see the island  in AD 875, but no one

visited it until 982. Three years later a few Norwegians went to live there. In 1261 the people in Greenland decided to join Norway. Norway and Denmark united in 1380. This union ended in 1814, and Greenland

stayed with Denmark. Greenland is fifty times larger than Denmark, but it is still part of this small country.   

1. When you study a map of the world, you may notice that Greenland _____.

A. is the greatest country in Europe

B. lies just on top of Europe

C. is connected with Denmark and Norway

D. mostly lies within the Arctic Circle

2. What will you probably see when you come to the southwest of Greenland in summer?

A. Forests of very low trees.

B. Nothing but ice sheet everywhere.

C. Very low plants along the seaside.

D. Snow that covers everything there.

3. When did Europeans begin to live in Greenland?

A. In AD 875.

B. In AD 982.

C. In AD 1261.

D. In AD 985.

4. How long did Greenland stay with Norway?

A. About 120 years.

B. About 400 years.

C. About 550 years.

D. About 500 years.

5. Which of the following is NOT right?

A. Greenland now belongs to Denmark.

B. Norway and Denmark have been one countrysince 1380.

C. Norway and Demnark didn't unite until 1380.

D. The area of Denmark is one-fifty-first of that of Greenland.

填空题