问题 填空题

(1)、①用肼(N2H4)为燃料,四氧化二氮做氧化剂,两者反应生成氮气和气态水。

已知:N2(g)+2O2(g)=N2O4(g)  ΔH=+10.7kJ·mol-1

N2H4(g)+O2(g)=N2(g)+2H2O(g)  ΔH=-543kJ·mol-1

写出气态肼和N2O4反应的热化学方程式:                                

②已知四氧化二氮在大气中或在较高温度下很难稳定存在,其很容易转化为二氧化氮。试推断由二氧化氮制取四氧化二氮的反应条件(或措施):                         

(2)科学家制造出一种使用固体电解质的燃料电池,其效率更高,可用于航天航空。

图甲所示装置中,以稀土金属材料为惰性电极,在两极上分别通入CH4和空气,其中固体电解质是掺杂了Y2O3的ZrO2固体,它在高温下能传导阳极生成的O2-(O2+4e →2O2-)

①c电极为       ,d电极上的电极反应式为                            

②图乙是电解100mL 0.5mol·L-1 CuSO4溶液,a电极上的电极反应式为          。若a电极产生56mL(标准状况)气体,则所得溶液的pH=     (不考虑溶液体积变化),若要使电解质溶液恢复到电解前的状态,可加入       (选填字母序号)

a.CuO    b.Cu(OH)2     c.CuCO3     d.Cu2(OH)2CO3

答案

(14分)

(1)①2 N2H4(g) +  N2O4(g)= 3N(g)+4H20(g) △H=-1096.7KJ·mol-1(2分)

②加压、降温(各1分)

(2)①正极(2分)  CH4 - 8e- + 402-=CO2+2H2O (2分)

②4OH- 4e-=2H2O+O2 (2分)  1 (2分)  a、c (2分)

题目分析:(1)①a、N2(g)+2O2(g)=N2O4(g)△H=10.7kJ·mol-1;b、N2H4(g)+O2(g)=N2(g)+2H2O(g)△H=-543kJ·mol-1

依据盖斯定律b×2-a得到  2N2H4(g)+N2O4(g)=3N2(g)+4H2O(g)△H=-1096.7KJ·mol-1

答案为:2N2H4(g)+N2O4(g)=3N2(g)+4H2O(g)△H=-1096.7KJ·mol-1

②四氧化二氮在大气中或在较高温度下很难稳定存在,它很容易转化为二氧化氮,由二氧化氮制取四氧化二氮,2NO2N2O4,反应是放热反应,反应前后气体体积减小所以反应条件为:增大压强、降温都有利于反应正向进行;

故答案为:增大压强、降温;

(2)①图1是原电池,依据电流流向是从正极流向负极,c电极为正极,氧气得到电子发生还原反应,d电极为电池负极甲烷是电子发生还原反应,在两极上分别通入CH4和空气,其中固体电解质是掺杂了Y2O3的ZrO2固体,它在高温下能传导阳极生成的O2离子,结合电子守恒写出电极反应为:CH4- 8e-+4O2=CO2+2H2O;

答案为:正极; CH4- 8e-+4O2=CO2+2H2O;

②如图2所示电解100mL0.5mol?L-1CuSO4溶液,发生的电解池反应为:2CuSO4+2H2O2Cu+O2↑+2H2SO4,与电源正极相连的为阳极,溶液中 氢氧根离子是电子发生氧化反应,电极反应为:4OH-4e=2H2O+O2↑;若a电极产生56mL(标准状况)气体为氧气,物质的量为0.0025mol,消耗氢氧根离子物质的量为0.01mol,溶液中生成氢离子物质的量为0.01mol,c(H)==0.1mol·L-1,PH=-lg0.1=1;则所得溶液电解过程中CuSO4溶液每损失2个Cu原子,就损失2个 O原子,相当于损失一个CuO,为了使CuSO4溶液,恢复原浓度,应加入CuO,也可以加入CuCO3,符合恢复溶液浓度的定量关系,但不能加入Cu(OH)2、Cu2(OH)2CO3,因为CuCO3+H2SO4CuSO4+CO2↑+H2O,相当于加CuO,而Cu(OH)2+H2SO4CuSO4+2H2O、Cu2(OH)2CO3+2H2SO4=2CuSO4 +CO2↑+3H2O,除增加溶质外还增加了水;选ac.

答案为:4OH- 4e-=2H2O+O2 ;1;ac;

单项选择题
填空题

[A] Possible ways to keep free from Alzheimer’s

[B] Deficiency of data-collecting in the study

[C] The new findings of ineffectiveness of past cures

[D] Weak evidence of the research

[E] How the new analysis coming from

[F] Future direction of the research concerned

[G] Traditional beliefs in preventive measures

Lifestyle May Not Prevent Alzheimer’s

A comprehensive analysis by an independent government panel has found that there is not enough scientific evidence to date to support the advice doctors currently give—such as exercising, doing crossword puzzles or eating a Mediterranean-style diet—for preventing or controlling symptoms of Alzheimer’s disease and dementia.

(41)______

As rates of age-related dementia and Alzheimer’s disease have continued to rise in the U.S.—largely because Americans are living longer and the over-65 population has swelled to record highs—researchers have worked relentlessly to understand the causes of these mind- robbing diseases and to help prevent or slow their progression. To clarify the state of the current evidence and offer physicians clearer treatment guidelines, the National Institutes of Health (NIH) in early 2009 commissioned a detailed analysis of existing studies, covering 165 papers published between 1984 and 2009.

(42)______

For years, the prevailing hypothesis has been "Use it or lose it" when it comes to avoiding gradual age-related mental decline. Data has associated behaviors such as keeping the mind actively engaged throughout life, staying physically active, eating certain foods and supplementing the diet with specific vitamins and nutrients with lower rates of dementia in old age. These lifestyle factors appeared to limit cognitive decline of various kinds, from occasional "senior moments" to the more serious episodes of cognitive impairment that can be a prelude to Alzheimer’s disease.

(43)______

Now researchers at Duke University report in the current issue of the Annals of Internal Medicine that the data on the preventive effects of lifestyle factors is not as p as they had thought. Led by Brenda Plassman, a professor of psychiatry and behavioral sciences, the study authors analyzed decades’ worth of research, including observational studies in which scientists looked retrospectively at a group of participants to tease out associations between certain behaviors (like exercise) and selected effects (like scores on tests of memory and cognitive skills), as well as the more definitive clinical trials that randomly assign volunteers to intervention or control groups and then assess how the intervention affects cognitive ability.

(44)______

Overall, the researchers say they were dismayed with the paucity and weakness of the existing evidence. "When we applied rigorous but consistent standards to review all the studies, we found that there was not sufficient evidence to recommend any single activity or factor that was protective of cognitive decline later in life, " says Plassman.

(45)______

However weakly, though, the review did support what doctors know about risk factors for cognitive decline: smoking, diabetes, depression, metabolic syndrome and specific gene variants were all linked with increased risk of developing Alzheimer’s disease. In addition, preventive behaviors such as eating a Mediterranean diet, exercising, maintaining cognitive engagement (doing puzzles, learning new things) and fostering extensive social relationships were linked to a lower risk.

The problem is that none of these relationships were particularly robust, the authors say. And none were p enough to justify recommending the behaviors to people who want to prevent or slow down the onset of dementia. The findings led the NIH to issue Monday’s state-of-the-science statement, in which the agency notes, "Currently, firm conclusions cannot be drawn about the association of any modifiable risk factor with cognitive decline or Alzheimer’s disease." Although the statement does not constitute an official policy or government recommendation, it serves as a guideline for doctors advising patients about the best evidence on the role of lifestyle factors in Alzheimer’s prevention.

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