题干

北京奥运会开幕式在李宁点燃鸟巢主火炬时达到高潮。奥运火炬采用的是环保型燃料——丙烷,其燃烧时发生反应的化学方程式为。下列说法中不正确的是( )

A:火炬燃烧时化学能只转化为热能

B:所有的燃烧反应都会释放热量

C:1 mol C3H8和5 mol O2所具有的总能量大于3 mol CO2和4 mol H2O所具有的总能量

D:丙烷完全燃烧的产物对环境无污染,故丙烷为环保型燃料

上一题 下一题 0.0难度 选择题 更新时间:2015-03-24 01:32:22

答案(点此获取答案解析)

A

同类题3

根据短文内容的理解,选择正确答案。

    It is fun being a vet (兽医). I like it because although it is hard work, every day is different! It all depends on what is wrong with the animals that come in.

    At my clinic(诊所), I work long days on Mondays, Wednesdays and Fridays, and short days on Tuesdays, Thursdays and Saturdays. Sunday is my day off so I can spend some time with my family.

    My day at my clinic begins at 7 am. My clerk opens the door, turns on some music, and makes everyone a cup of tea or coffee. My assistant (助手) cleans and feeds the animals. The phones start to ring and people make appointments. This is a very busy time of day!

    At 9 am, pet owners start to arrive with their sick pets. Appointments take up the whole morning. At midday, I stop for two hours. I don't examine(检查)any new sick animals. I use these two hours to have lunch and do all my paperwork.

    At 2 pm. I start to see sick animals again. At 5 pm, three students from a local school who love animals arrive to help out. They are very kind and warm-hearted. I am always happy to see their smiling faces!

From 5 pm to 7pm, I continue to see sick animals. Then, at 7 pm, we close our doors and the clean-up begins! We tidy the clinic, and feed and clean the animals. Of course, we also stroke (轻抚) them and give them hugs! Then, we turn off the lights and go home. This is the type of day I want to have.

    I'm very happy being a vet, though unexpected things sometimes happen!