问题 填空题

如表所示的数据是破坏1mol物质中的化学键所消耗的能量

物质Cl2Br2I2HClHBrHIH2
能量(kJ)243193151432366298436
(1)根据上述数据,物质本身具有的能量最低的是______(填序号).

A.H2

B.Cl2

C.Br2

D.I2

(2)下列氢化物中,最稳定的是______(填序号).

A.HCl    

B.HBr    

C.HI

(3)X2+H2⇌2HX(X代表Cl、Br、I)的反应是______(填“吸热”或“放热”)反应.

(4)相同条件下,X2(X代表Cl、Br、I)分别与氢气反应,若消耗等物质的量的氢气时,放出或吸收热量最多的是______.

答案

(1)根据表中数据可知,破坏1mol氢气中的化学键所消耗的能量最高,则说明氢气最稳定,具有的能量最低,故选:A;

(2)根据表中数据可知,破坏1mol氯化氢中的化学键所消耗的能量最高,则说明HCl最稳定,故选:A;

(3)反应X2+H2=2HX,若X2为Cl2,旧键断裂吸收的热量:243kJ+436kJ=679kJ,新键生成释放的热量:432kJ×2=864kJ,反应放出的热量为185kJ,

反应X2+H2=2HX,若X2为Br2,旧键断裂吸收的热量:193kJ+436kJ=629kJ,新键生成释放的热量:366kJ×2=732kJ,反应放出的热量为103kJ,

反应X2+H2=2HX,若X2为I2,旧键断裂吸收的热量:151kJ+436kJ=587kJ,新键生成释放的热量:298kJ×2=596kJ,反应放出的热量为9kJ,

因此三个反应都为放热反应,故答案为:放热反应;

(4)因化学反应所吸收或放出的能量即为反应热,反应热等于反应中断裂旧化学键消耗的能量之和与反应中形成新化学键放出的能量之和的差,以氯元素为例计算断开1molCl-Cl键和H-H键需吸收能量:243kJ+436kJ=679kJ,而形成2molHCl放出的能量为2×432kJ=864 kJ,所以在Cl2+H2=2HCl反应中放出864kJ-679kJ=185kJ的热量,同理可计算在Br2+H2=2HBr、I2+H2=2HI反应中分别放出103kJ、9kJ的热量.故答案为:Cl2

阅读理解

Several parents and children escaped the summer heat and enjoyed a refreshing “Leap Into a Good Book”.About 30 children and parents gathered as volunteers for both agencies.

After the readings,refreshments (点心) were offered and children and parents were given books,a gift bag and a bookmark with information on adult literacy (读写能力) programs.

Learn to Read of Northwest Florida Inc.and Even Start coordinated the event with hopes that combining their programs will help target functionally illiterate adults and their families.A functionally illiterate adult is one who has reading skills below a seventh­grade level.That often means they have difficulty filling out job applications,understanding a lease,reading medication labels or to their children.

Merelin Hernandez,9,a fourth­grader at Warrington Elementary School,understands the importance of reading.She also says it makes her happy when she is bored.“Reading helps me go to another grade,”she says.“I feel proud when I get a B because then I know I am reading well.”Monae Walker,7,a student at Oakcrest Elementary School,says reading teaches her and makes her happy.

Learn to Read of Northwest Florida Inc.provides one­on­one tutoring for basic reading and writing skills to adults 16 and older who are not in school.Tutors go through a 12­hour workshop and tutor their students 3 hours per week.The program currently has 150 active tutors.

Even Start is a family education program at McMillan Learning Center,which offers adult education classes and infant,toddler and prekindergarten services at no cost to families.Linda Harris,a teacher in charge of the Escambia Even Start program,says the program equips parents so they can help their children.

小题1:The event “Leap Into a Good Book”________.

A.was mainly held by Learn to Read

B.targeted functionally literate parents

C.was attended by about 30 volunteers

D.was held to enjoy reading in summer小题2:According to the passage,a functionally illiterate adult________.

A.has skills below a seventh­grade level

B.has never got school education

C.has no ability to recognize English words

D.can’t fill out a job application小题3:According to the passage,Monae Walker________.

A.was attending the one­on­one tutoring

B.was a school­leaver

C.was having a good time there

D.read books with her parents小题4:According to the passage,Even Start can________.

A.make parents able to help their children

B.educate children how to use words

C.offer some services for families in life

D.offer a good place for children

问答题 简答题