问题 选择题

1g氢气在氧气中完全燃烧生成气态水,放出热量120.9 kJ,则(  ) 

A.反应的热化学方程式:2H2(g)+O2(g)=2H2O(g) ΔH= +483.6 kJ·mol?1

B.氢气的燃烧热为241.8 kJ·mol?1

C.1 mol H2O(1)的能量大于1 mol H2O(g)的能量

D.2 mol H2和1 mol O2的能量总和大于2 mol H2O(g)的能量

答案

答案:D

A 错 反应是放热反应,ΔH= -483.6 kJ·mol?1

B错氢气的燃烧热是1mol氢气完全燃烧生成液态水时放出的热量,241.8 kJ·mol?1是生成气态水时放出的热量

C 错液态水比气态水稳定,能量越低越稳定,所以1 mol H2O(1)的能量小于1 mol H2O(g)的能量

D 对此反应是放热反应,反应物的能量应高于生成物的能量

阅读理解

阅读理解。

     Are you interested in country music? I like it very much! It will take me away for a while after I am

tired. The guitars and songs will take me to mountains and fields.

     Country music usually talks of everyday life and feelings. It's the spirit of America, easy to understand,

slow and simple.

      Country music developed in the Southern United States. It was the folk music of American

countryside. Many of songs tell about the lives of farmers.They talk about love, crops or death.

      The life of the countryside can be hard, so the words in country music are often sad. At first, people

played the music only at family parties. But it became more popular later. In the 1920s, people played

country songs on the radio, and they made them into records.

     When people in the countryside moved to towns and cities to look for work, they took their music

with them. Country music continued to change and became popular across America.

     John Denver was one of America's most famous country singers in the 1970s. His song "Take Me

home, Country Roads" is well-known and people still play it today.

1. Country music is usually about _____. [ ]

A. everyday life and feelings

B. farmers' feelings

C. the lives of workers

2. Country music developed _____. [ ]

A. in John Denver's city

B. in the Southern United States

C. in the Northern United States

3. People began to make country song records _____.[ ]

A. in the 1920s

B. in 1920

C. in the 1970s

4. Why did Country music become popular in America? [ ]

A. Because city people liked the music.

B. Because farmers moved to cities with their music and it continued to change.

C. Because country music talked about city people's lives.

5. Who is famous for the song "Take Me Home, Country Roads"? [ ]

A. A farmer in the countryside.

B. A person who moved to towns.

C. John Denver.

选择题