问题 选择题

下列说法正确的是(      )

A.在100 ℃、101 kPa条件下,液态水的气化热为40.69 kJ·mol-1,则H2O(g)H2O(l) 的 ΔH =" —40.69" kJ·mol-1

B.在25℃、101kPa,2mol S的燃烧热是1mol S的燃烧热2倍

C.CH4(g) +2O2(g) =CO2(g) +2H2O(g) ΔH=-akJ·mol-1,这里ΔH代表燃烧热

D.已知:

共价键C-CC=CC-HH-H
键能/ kJ·mol-1348610413436
 

则可以计算出反应的ΔH为-384 kJ·mol-1

答案

答案:A

题目分析:A.气化热是1mol的物质在一定的条件下由液态变为气态所吸收的热量。在100 ℃、101 kPa条件下,液态水的气化热为40.69 kJ·mol-1,则物质由气态转化为液态释放热量40.69 kJ。则H2O(g) H2O(l) 的ΔH =" —40.69" kJ·mol-1。正确。B.燃烧热是1mol的物质完全燃烧产生稳定的氧化物时所释放的热量。在25℃、101kPa,2mol S的燃烧放出的热量是1mol S的燃烧放出热量2倍,但是燃烧热是相同的。错误。C.CH4(g) +2O2(g) =CO2(g) +2H2O(g)  ΔH=-akJ·mol-1,这里ΔH并不代表燃烧热。因为水在气态时是不稳定的状态,液态才是水的稳定状态。错误。D.在苯分子中不含C-C及C=C,而是存在一种介于单键与双键之间的一种特殊的化学键。因此根据表格提供的数据不能计算出该反应的反应热。正确。

完形填空

Long ago, in a far-away place, an old tribal chief found himself terminally ill. So he called three most promising young villagers to his bedside and said, “As I ____小题1:____(leave) you soon, I hope you can do one more thing for me. Young men, you three are all ____小题2:____(usual) strong and resourceful, so I’d like you to strive to climb that high mountain we have always been worshipping _____小题3:_____ a sacred place. Try to reach the top and then turn back to tell me about your findings. 

Three days later, the first young man returned smartly dressed and said ___小题4:____(smile),

“Lord, I’ve been to the mountaintop____小题5:____I saw flowers of all sorts, spring water and singing birds. That’s a real nice place.”

The old tribal chief replied with a smile, “Son, I’ve been there before. it's not the mountaintop ____小题6:____the foot of the mountain. You can leave now.”

A week later, the second young man also returned. “Lord, I’ve been to the mountaintop ___小题7:___ a forest of tall pine trees and vultures circling in the air. That’s a really nice place.”

“What a pity!” said the chief. “Son, you’ve been halfway up the mountain rather than to the summit. Now you can leave .”

A month later, the third young man showed up in rags, his hair off-colored but his eyes clear and bright.  

“Lord, I succeeded in reaching the summit. There was nothing there but the highland wind and the blue sky ___小题8:___(hang) over the land.”

“So you saw nothing at all? Not even ___小题9:___butterfly?”

“No, Lord, nothing. All you can see is yourself. You just feel how insignificant you are in this infinite universe ___小题10:__ standing at the top!” 

“Son, you’ve reached the real mountaintop. Congratulations! You will be undoubtedly made our new tribal chief!”

单项选择题