问题 填空题

节能减排是当今社会的热门话题,研发混合动力汽车对于中国汽车业的未来具有重要的战略意义。混合动力汽车持续工作时间长,动力性好的优点,无污染、低噪声的好处,汽车的热效率可提高10%以上,废气排放可改善30%以上,某种混合动力汽车的动力系统由“1.6L汽油机十自动变速器十20kW十200V镍氢电池”组成。

①混合动力汽车所用的燃料之一是乙醇,lg乙醇完全燃烧生成CO2气体和液态H2O放出30.0kJ热量,写出乙醇燃烧的燃烧热的热化学方程式            

②镍氢电池的使用可以减少对环境的污染,它采用储氢金属为负极,碱液NaOH为电解液,镍氢电池充电时发生反应                                  。其放电时的正极的电极反应方程式为        

③常温下,同浓度的Na2CO3溶液和NaHCO3溶液的pH都大于7,两者中哪种的pH更大,其原因是    。0.1mol·L-1 Na2CO3中阴离子浓度大小关系是   ,向0.1mol·L-1 NaHCO3溶液中滴入少量氢氧化钡溶液,则发生反应的离子方程式为:             

(2)二氧化锰、锌是制备干电池的重要原料,工业上用软锰矿(含MnO2)和闪锌矿(含ZnS)

联合生产二氧化锰、锌的工艺如下:

①操作Ⅰ需要的玻璃仪器是      

②软锰矿(含MnO2)和闪锌矿与硫酸反应的化学方程式为       ,上述电解过程中,当阴极生成6.5g B时阳极生成的MnO2的质量为      

③利用铝热反应原理,可以从软锰矿中提取锰,发生的化学方程式为      

答案

(1)①C2H5OH(l)+3O2(g)=2CO2(g) +3H2O(l);△H=-1380KJ/mol  (2分)

② NiO(OH) + H2O+ e- = Ni(OH)3 + OH- ;    (2分)

③Na2CO3,CO32- 水解比HCO3- 水解程度大,产生的OH- 更多,所以Na2CO3溶液的碱性比NaHCO3的大,PH大。      C(CO32-)﹥C(OH-)﹥C(HCO3-) (各1分)

Ba2+ + 2OH- + 2HCO3- =BaCO3↓+ CO32- + 2H2O   (2分)

(2)① 漏斗、烧杯、玻棒  (写全得1分) 

②MnO2 +ZnS +2H2SO4==MnSO4+ZnSO4+ S↓+2H2O; 8.7 g (各2分)

③ 3MnO2 + 4Al2Al2O3 + 3Mn   (2分)

题目分析:(1)①燃烧热指是1mol乙醇完全燃烧生成二氧化碳和液态水时放出的热量,故把1g换算成成46g,热量数值乘以46得乙醇的燃烧热;②放电时的反应为充电时的逆反应,放电时正极发生还原反应故NiO(OH)得电子发生还原反应生成Ni(OH)2;③根据两者水解程度的大小判断溶液pH的大小;水解是微弱的,碳酸钠溶液中主要存在的阴离子是碳酸根离子,碳酸根离子发生第一步水解生成碳酸氢根离子和氢氧根离子,碳酸氢根离子再发生水解生成碳酸分子和氢氧根离子,故C(CO32-)﹥C(OH-)﹥C(HCO3-);氢氧化钡溶液是少量的,可假设氢氧化钡的物质的量为1mol,2mol的OH-消耗2mol的HCO3-生成2mol的CO32-,1mol的钡离子只和1mol的碳酸根离子反应生成1mol的碳酸钡沉淀,故Ba2+ + 2OH- + 2HCO3- =BaCO3↓+ CO32- + 2H2O;(2)①操作Ⅰ是过滤,故需要漏斗做成过滤器、烧杯、玻璃棒引流;②反应物为MnO2和ZnS,产物MnSO4+ZnSO4,故二氧化锰发生了还原反应,发生氧化反应的是负二价的硫,氧化后生成不溶水的硫单质,故为MnO2 +ZnS +2H2SO4==MnSO4+ZnSO4+ S↓+2H2O;根据信息联合生产二氧化锰、锌,故阴极生成6.5g的锌,物质的量为0.1mol,转移电子的物质的量为0.2mol,当MnSO4得到0.2mol电子时生成0.1mol的MnO2,故质量为8.7g;③根据铝热反应得铝和二氧化锰高温下反应生成锰单质和氧化铝;

阅读理解

阅读理解。

     The teacher stood before his class of 30 students and was about to hand out the final exam papers. "I

know how hard you have all worked to prepare for this test," he said. "Arid because I know you are all able

to understand this material, I am ready to offer a B to anyone who would prefer not to take the test."

     A number of students jumped up to thank the teacher and left the classroom. The teacher looked at the

remaining (余下的) students and said, "Does anyone else want to get a B? This is your last chance." Two

more students decided to go. Seven students stayed. The teacher then handed out the papers. There were

only three sentences which were typed on the paper: Congratulations! You have received an A in this class.

Keep believing in yourself.

     I never had a teacher who gave a test like that, but I think that it is a test that any teacher could and

should give. Students who do not have confidence in what they have learned are B students at most.

     The same is true for students in real life. The A students are those who believe in what they are doing

because they have learned from both successes and failures. They have learned life's lessons, whether from

formal education or from even is in their lives, and have become better people. Scientists say that by the age

of eight, 80% of what we believe about ourselves has already been formed. You are a big kid now, and you

realize that you have some limits (局限). However, there is nothing you can't do or leant to be. Sir Edmund

Hillary, the first person to reach the top of Mount Qomolangma (珠穆朗玛峰) said, "We do not conquer the

mountain, but ourselves."

1. Why did some students leave the classroom?

A. Because they were happy with the mark the teacher would give them.

B. Because they were allowed to take another easier exam later on.

C. Because they knew the teacher didn't like them to take the test.

D. Because they thought the exam was too easy to be worth a try.

2. Why did the teacher give the remaining students an A? 

A. Because they answered all the questions in the exam correctly.

B. Because they had been promised an A by the teacher before.

C. Because they were confident in what they had learned.

D. Because they had been working hard for each exam.

3. What does the underlined word "conquer" mean in the passage?

A. 发现

B. 控制

C. 探索

D. 征服

4. What is the writer's purpose of writing the passage?

A. He wants us to know what our limits are.

B. He wants us to learn to believe in ourselves.

C. He wants us to receive formal education.

D. He wants us to learn from B students.

单项选择题 B1型题