问题 填空题

(8分)短周期元素A、B、C、D在周期表中位置如图所示,其中元素D原子最外层有3个电子。

(1)A与氢元素可以形成很多化合物,在这些化合物中都含有   (填“共价”或“离子”)键;B在元素周期表中位于      族; 

(2)B、C、D形成的简单离子的半径由大到小依次为               。(填相应的离子符号)

(3)D的最高价氧化物对应的水化物与NaOH溶液反应的化学方程式是                 

(4)已知298K时,Fe(s) + O2(g) ="=" FeO(s)    ΔH= -300.0 kJ·mol1

2D(s) + O2(g) ="=" D2O3(s)   ΔH= -1675.7 kJ·mol1

写出D单质和FeO反应的热化学方程式是                               

答案

(8分)(1)共价键; VA族;(各1分) (2)Cl->N3->Al3+(2分)

(3)Al(OH)3+NaOH=NaAlO2 +2H2O(2分)

(4)2Al(s)+3FeO(s)=Al2O3(s)+3Fe(s)  ΔH= -775.7kJ·mol1(2分)

题目分析:D元素的最外层电子数是3个,根据D的位置可判断,D是第三周期元素。所以D是Al,则A是C、B是N、C是Cl。

(1)碳元素形成的氢化物中都含有C-H极性键;氮元素属于第ⅤA族。

(2)核外电子排布相同的微粒,其微粒半径岁原子序数的增大而减小,所以B、C、D形成的简单离子的半径由大到小依次为Cl->N3->Al3+

(3)氢氧化铝是两性氢氧化物,能和氢氧化钠溶液反应,化学方程式是Al(OH)3+NaOH=NaAlO2 +2H2O。

(4)根据盖斯定律可知,②-①×3即得到2Al(s)+3FeO(s)=Al2O3(s)+3Fe(s),所以该反应的反应热是△H=-1675.7kJ/mol+300.0kJ/mol×3=-775.7kJ/mol。

点评:本题主要是元素“位、构、性”三者关系的综合考查,比较全面考查学生有关元素推断知识和灵活运用知识的能力。该题以“周期表中元素的推断”为载体,考查学生对元素周期表的熟悉程度及其对表中各元素性质和相应原子结构的周期性递变规律的认识和掌握程度。考查了学生对物质结构与性质关系以及运用元素周期律解决具体化学问题的能力。

单项选择题 A1/A2型题
单项选择题

A pair of dice, rolled again and again, will eventually produce two sixes. Similarly, the virus that causes influenza is constantly changing at random and, one day, will mutate in a way that will enable it to infect billions of people, and to kill millions. Many experts now believe a global outbreak of pandemic flu is overdue, and that the next one could be as bad as the one in 1918, which killed somewhere between 25m and 50m people. Today however, advances in medicine offer real hope that another such outbreak can be contained-if governments start preparing now.

New research published this week suggests that a relatively small stockpile of an antiviral drug-as little as 3m doses--could be enough to limit sharply a flu pandemic if the drugs were deployed quickly to people in the area surrounding the initial outbreak. The drug’s manufacturer, Roche, is talking to the World Health Organisation about donating such a stockpile.

This is good news. But much more needs to be done, especially with a nasty strain of avian flu spreading in Asia which could mutate into a threat to humans. Since the SARS outbreak in 2003 a few countries have developed plans in preparation for similar episodes. But progress has been shamefully patchy, and there is still far too little international coordination.

A global stockpile of drugs alone would not be much use without an adequate system of surveillance to identify early cases and a way of delivering treatment quickly, If an outbreak occurred in a border region, for example, a swift response would most likely depend on prior agreements between different countries about quarantine and containment.

Reaching such agreements is rarely easy, but that makes the task all the more urgent, Rich countries tend to be better prepared than poor ones, but this should be no consolation to them. Flu does not respect borders. It is in everyone’s interest to make sure that developing countries, especially in Asia, are also well prepared. Many may bridle at interference from outside. But if richer nations were willing to donate anti-viral drugs and guarantee a supply of any vaccine that becomes available, poorer nations might be willing to reach agreements over surveillance and preparedness.

Simply sorting out a few details now will have lives (and recriminations) later. Will there be enough ventilators, makes and drugs Where will people be treated if the hospitals overflow Will food be delivered as normal Too many countries have no answers to these questions.

According to the text, it is upsetting that ()

A. the flu-catching is more pervasive the world over

B. the cause of initial outbreak has not been identified

C. global co-ordination is yet to well develop

D. people still have no answers concerning surveillance and containment