已知充分燃烧ag乙炔气体时生成1mol二氧化碳气体和液态水，并放出热量bkJ，则乙炔燃烧的热化学方程 式正确的是 [ ]
A．2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l) △H = -2bkJ/mol
B．C2H2(g)+5/2O2(g)=2CO2(g)+H2O(l) △H =2bkJ/mol
C．2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l) △H=-4bkJ/mol
D．2C2H2(g)+5O2(g)=4CO2(g)+2H2O(l) △H =bkJ/mol
答案：C
| 根据对话内容及方框中所给的句子补全对话。其中有一项是多余的。 | |
| (After class, Wang Feng is having a conversation with his foreign teacher Alice from America.) Wang Feng: You know, how to get along with others is very important in our daily life. Alice: Yes.1._______ Wang Feng: I am going abroad. 2._______ Alice: OK. "Good morning.good afternoon, good evening!" are said to one you know or anyone you are passing quickly. "How do you do?" is used when you are not in such a hurry in formal occasion ( 正式场合). 3._______ Wang Feng: In your country, what should you do when you meet 'someone for the first time? Alice: Shake hands. Wang Feng: How to shake hands? Alice: Adults offer hands to children first.A woman offers her hands first.An older person initiates a handshake with a younger one. The more important person is the first to offer his or her hand. Wang Feng: 4._______ Alice: A man is always introduced to a woman. The younger is always introduced to an older, and a less important person is always introduced to a more important one. Wang Feng: Thank you for telling me so much about western manners. Alice: 5._______ | |
|