问题 填空题

(14分)高炉炼铁中发生的基本反应之一如下: 

FeO(固)+CO(气)  Fe(固)+CO2(气) △H﹤0。已知1100℃时,K=0.263。化学平衡常数只与温度有关,不随浓度和压强的变化而变化。

(1)其平衡常数可表示为K=_______  ,若温度升高,化学平衡移动后达到新的平衡,平衡常数K值_____(本小题空格填写:增大、减小或不变)

(2)1100℃时,测得高炉中c(CO2)="0.025" mol·L-1,c(CO)=0.1mol·L-1,在这种情况下该反应是否处于化学平衡状态_______   (选填“是”或“否”),此时化学反应速率是 υ正___υ逆(选填大于、小于或等于)其原因是___________。

(3)若平衡时,保持容器容积不变,使容器内压强增大,则平衡_______

A. 一定向正反应方向移动          B. 一定向逆反应方向移动

C. 一定不移动                    D. 不一定移动

(4)欲提高CO的平衡转化率,可采取的措施(    )

A. 减少Fe             B. 增加FeO     

C. 移出部分CO2         D. 提高反应的温度 

E. 减小容器的体积      F. 加入合适的催化剂

答案

(14分,每空2分)(1)K=c(CO2)/c(CO) ;减小

(2) 否 大于 C(CO2)/C(CO)﹤0.263。(3)D (4)C

(1)平衡常数是在一定条件下,可逆反应达到平衡状态时,生成物浓度的幂之积和反应物浓度的幂之积的比值,所以K=c(CO2)/c(CO) ;正反应是放热反应,所以升高温度,平衡向逆反应方向移动,平衡常数减小。

(2)当c(CO2)="0.025" mol·L-1,c(CO)=0.1mol·L-1是K=0.025÷0.1=0.25<0.263,所以反应还没有达到平衡状态。

(3)保持容器容积不变,使容器内压强增大,但物质的浓度不一定变化,所以平衡不一定发生移动,答案选D。

(4)铁、FeO都是是固体,不能影响平衡状态;移出部分CO2 ,即降低生成物的浓度,平衡向正反应方向进行,转化率增大;升高温度,平衡向逆反应方向移动,转化率降低;反应前后条件不变,减小容器的体积,平衡不移动;催化剂不能改变平衡状态,所以正确的答案选C。

选择题
单项选择题

Elections often tell you more about what people are against than what they are for. So it is with the European ones that took place last week in all 25 European Union member countries. These elections, widely trumpeted as the world’s biggest-ever multinational democratic vote, were fought for the most part as 25 separate national contests, which makes it tricky to pick out many common themes. But the pest are undoubtedly negative. Europe’s voters are angry and disillusioned-and they have demonstrated their anger and disillusion in three main ways.

The most obvious was by abstaining. The average overall turnout was just over 45%, by some margin the lowest ever recorded for elections to the European Parliament. And that average disguises some big variations: Italy, for example, notched up over 70%, but Sweden managed only 37%. Most depressing of all, at least to believers in the European project, was the extremely low vote in many of the new member countries from central Europe, which accounted for the whole of the fall in turnout since 1999. In the biggest, Poland, only just over a fifth of the electorate turned out to vote. Only a year ago, central Europeans voted in large numbers to join the EU, which they did on May 1st. That they abstained in such large numbers in the European elections points to early disillusion with the European Union-as well as to a widespread feeling, shared in the old member countries as well, that the European Parliament does not matter.

Disillusion with Europe was also a big factor in the second way in which voters protested, which was by supporting a ragbag of populist, nationalist and explicitly anti-EU parties. These ranged from the 16% who backed the UK Independence Party, whose declared policy is to withdraw from the EU and whose leaders see their mission as "wrecking" the European Parliament, to the 14% who voted for Sweden’s Junelist, and the 27% of Poles who backed one of two anti-EU parties, the League of Catholic Families and Selfdefence. These results have returned many more Eurosceptics and trouble-makers to the parliament: on some measures, over a quarter of the new MEPS will belong to the "awkward squad". That is not a bad thing, however, for it will make the ’parliament more representative of European public opinion.

But it is the third target of European voters’ ire that is perhaps the most immediately significant, the fact that, in many EU countries, old and new, they chose to vote heavily against their own governments. This anti-incumbent vote was p almost everywhere, but it was most pronounced in Britain, the Czech Republic, Germany, Poland and Sweden. The leaders of all the four biggest European Union countries, Tony Blair in Britain, Jacques Chirac in France, Gerhard Schroder in Germany and Silvio Berlusconi in Italy, were each given a bloody nose by their voters.

The big question now is how Europe’s leaders should respond to this. By a sublime (or terrible) coincidence, soon after the elections, and just as The Economist was going to press, they were gathering in Brussels for a crucial summit, at which they are due to agree a new constitutional treaty for the EU and to select a new president for the European Commissi6n. Going into the meeting, most EU heads of government seemed determined to press ahead with this agenda regardless of the European elections--even though the atmosphere after the results may make it harder for them to strike deals.

The relationship between the opening paragraph and the rest of text is that ()

A. a proposal is advanced in the first paragraph and then negated in the following paragraphs

B. an prophecy is revealed and then proved with concrete examples

C. a generalization is made in the first paragraph and then elaborated in the following paragraphs

D. a proposition is introduced in the first paragraph and then explained in details in the following paragraphs