问题 选择题

下列离子方程式正确的是                  

A.用稀氢氧化钠溶液吸收二氧化氮:2OH+2NO2 = NO+2NO↑+H2O

B.NH4HCO3溶液与足量KOH浓溶液共热:NH+OHNH3↑+H2O

C.铁溶于足量的稀硝酸,溶液变黄:3Fe+8H+2NO= 3Fe2+2NO↑+4H2O

D.NaHSO4溶液与NaOH溶液混合:OH+H= H2O

答案

答案:D

题目分析:A项,氮元素化合价升降总数不相等、电子得失不守恒,且氮原子个数不守恒,二氧化氮与氢氧化钠溶液反应生成硝酸钠、亚硝酸钠和水,即2OH+2NO2 = NO+NO2+H2O,故A选项错误;B项,铵盐与强碱混合加热不是可逆反应,铵根离子与氢氧根离子能反应,碳酸氢根离子与氢氧根离子也能反应,不能漏写,即NH+HCO3+OH= CO32+NH3↑+H2O,故B选项错误;C项,亚铁离子与稀硝酸不能大量共存,易发生氧化还原反应,生成铁离子、一氧化氮和水,即Fe+4H+NO= Fe3+NO↑+2H2O,故C选项错误;硫酸氢钠是强酸酸式盐,能完全电离出钠离子、氢离子和硫酸根离子,具有强酸性,与氢氧化钠中和生成硫酸钠和水,因此反应为OH+H= H2O,故D选项正确。

单项选择题
填空题

(41)______

Through laziness and cowardice a large part of mankind, even after nature has freed them from alien guidance, gladly remain immature. It is because of laziness and cowardice that it is so easy for others to usurp the role of guardians, It is so comfortable to be a minor! If I have a book which provides meaning for me, a doctor who will judge my diet for me and so on, then I do not need to exert myself. I do not have any need to think; if I can pay, others will take over the tedious job for me. The guardians who have kindly undertaken the supervision will see to it that by far the largest part of mankind, including the entire "beautiful sex," should consider the step into maturity, not only as difficult but as very dangerous.

(42)______

It is difficult for the isolated individual to work himself out of the immaturity which has become almost natural for him. He has even become fond of it and for the time being is incapable of employing his own intelligence, because he has never been allowed to make the attempt. Statues and formulas, these mechanical tools of a serviceable use, or rather misuse, of his natural faculties, are the ankle-chains of a continuous immaturity. Whoever threw it off would make an uncertain jump over the smallest trench because he is not accustomed to such free movement. Therefore there are only a few who have pursued a firm path and have succeeded in escaping from immaturity by their own cultivation of the mind.

But it is more nearly possible for a public to enlighten itself: this is even inescapable if only the public is given its freedom. For there will always be some people who think for themselves, even among, the self-appointed guardians of the great mass who, after having thrown off the yoke of immaturity themselves, will spread about them the spirit of a reasonable estimate of their own value and of the need for every man to think for himself.

(43)______.

Through revolution, the abandonment of personal despotism may be engendered and the end of profit-seeking and domineering oppression may occur, but never a true reform of the state of mind. Instead, new prejudices, just like the old ones, will serve as the guiding reins of the great, unthinking mass. (44)______.

But I hear people clamor on all sides: Don’t argue ! The officer says: Don’t argue, drill! The tax collector: Don’t argue, pay! The pastor: Don’t argue, believe!... Here we have restrictions on freedom everywhere. Which restriction is hampering enlightenment, and which does not, or even promotes it I answer; The public use of a man’s reason must be free at all times, and this alone can bring enlightenment among men.

The question may now be put: Do we live at present in an enlightened age’

(45)______.

[A] All that is required for this enlightenment is freedom; and particularly the least harmful of that may be called freedom, namely, the freedom for man to make public use of his reason in all matters.

[B] Enlightenment is man’s leaving his self-caused immaturity. Immaturity is the incapacity to use one’s intelligence without the guidance of another. Such immaturity is self-caused if it is not caused by lack of intelligence, but by lack of determination and courage to use one’s intelligence without being guided by another. Have the courage to use your own intelligence! It is therefore the motto of the Enlightenment.

[C] The answer is: No, but in an age of enlightenment. Much still prevents men from being placed in a position to use their own minds securely and well in matters of religion. But we do have very definite indications that this field of endeavor is being opened up for men to work freely and reduce gradually the hindrances preventing a general enlightenment and an escape from self-caused immaturity.

[D] I call this soaring wealth and shrinking spirit "the American paradox." More than ever, we have big houses and broken homes, high incomes and low morale, secured rights and diminished civility. We excel at making a living but often fail at making a life. We celebrate our prosperity but yearn for purpose. We celebrate our freedoms but long for connection. In an age of plenty, we feel spiritual hunger.

[E] A public can only arrive at enlightenment slowly.

[F] After having made their domestic animals dumb and having carefully prevented these quiet creatures from daring to take any step beyond the lead-strings to which they have fastened them, these guardians then show them the danger which threatens them, should they attempt to walk alone. Now this danger is not really so very great; for they would presumably learn to walk after some stumbling. However, an example of this kind intimidates and frightens people out of all further attempts.

[G] Attitudes about divorce have dramatically changed. In the past, it was seen as the last resort of a woman who had been beaten up or cheated on. Women were victims. Today many women choose’ to get divorced because they think they will have a better life as a SINDI than by staying in a stale marriage. In 74 percent of eases it is women who now instigate divorce proceedings.

43()