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问题 选择题

1840年，瑞士化学家盖斯(G．H．Hess)从大量的实验事实中总结出了一条规律：化学反应不管是一步完成还是分几步完成，其反应焓变是相同的，即盖斯定律．盖斯定律在生产和科学研究中有很重要的意义，有些反应的反应焓变虽然无法直接测得，但可以利用盖斯定律间接计算求得．已知3．6 g碳在6．4 g氧气中燃烧，至反应物耗尽．共放出x kJ热量．已知单质碳的燃烧热为了y kJ·mol－1，则1 mol C与O2反应生成CO的反应焓变△H为    ( 　)

A．－y kJ·mol－1

B．－(10x－y)kJ·mol－1

C．－(5x－0．5y)kJ·mol－1

D．(10x－y)kJ·mol－1

答案

答案：C

3．6 g碳在6．4 g氧气中燃烧，生成物是CO2和CO，其中CO2是0.1mol，CO是0.2mol。所以根据反应c(s)＋O2(g)=CO2(g) △H＝－y kJ·mol－1可知，生成0.1molCO2放出的热量是0.1ykJ，所以生成0.2molCO放出的热量是xkJ－0.1ykJ，因此1 mol C与O2反应生成CO的反应焓变△H为－(5x－0．5y)kJ·mol－1，答案选C。

阅读理解

读下面的简历并回答问题。

     ①Hi! My name is Jenny. I am nearly l3 years old and I am in Grade l, NO. 3 Middle School. I have a

sister called Sooner and a cat called Campuses.Sooner is 10. I enjoying reading, swimming and playing

tennis. I also like blowing the flute (吹笛子) and playing the piano.

     ②Hi! My name is Sue and I am l4 years old. I am in Grade 2 at No. 14 Middle School and I have a

sister who is 8 years old. My hobbies are reading,running. I like running in races.

     ③Hi! My name is Ann and I am l5 years old. I am in Grade 3 at No. 110 Middle School. I am the only

girl out of four children in my family. I have three younger brothers-their names are Peter, Michael and

James.

     ④Hi! My name is Manthers and I am l6 years old. I have a brother, Bob, who is14. My hobbies are

riding a bike and playing computer games. I have two dogs named Choky and Nutty.

1. Who like playing the piano?

                                                                          

2. Who likes running in races? 

                                                                          

3. What are Choky and Nutty?

                                                                          

4. Who has sisters?

                                                                          

5. Who is the only girl of them? 

                                                                          
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单项选择题

根据颅内血肿引起颅高压或早期脑疝症状所需的时间，急性期血肿是指（）

A.<3h

B.<3日

C.3日至3周

D.>3周
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