问题 填空题

一定条件下,可逆反应N2+3H2⇌2NH3△H<0,达到平衡后,

(1)加催化剂,V、V都发生变化,且变化的倍数______(选填:相等.不相等)

(2)缩小体积使体系压强增大,则V______,V______(选填:增大、减小、不变)V变化的倍数______V变化的倍数(选填:大于、小于、等于)

(3)降温,V、______V______(选填:增大、减小、不变),

(4)恒容下再通入一定量的氮气,达新平衡时,N2转换率______,H2转化率______(选填:增大、减小、不变).

答案

(1)催化剂能同等程度的改变正逆反应速率,所以正逆反应速率变化的倍数相等,故答案为:相等;

(2)增大压强,增大了单位体积内活化分子的个数,所以正逆反应速率都增大,但正反应速率变化的倍数大于逆反应速率变化的倍数,所以平衡向正反应方向移动,

故答案为:增大;增大;大于;

( 3)降低温度,降低了正逆反应的活化分子百分数,所以正逆反应速率都减小,故答案为:减小;减小;

(4)恒容下再通入一定量的氮气,氮气浓度增大,平衡向正反应方向移动,所以氢气的转化率增大,但加入氮气大于氮气转化的量,所以氮气的转化率减小,

故答案为:减小;增大.

阅读理解

Modern inventions have speeded up people’s lives amazingly. Motor-cars cover a hundred miles in little more than an hour, aircraft cross the world inside a day, while computers operate at lightning speed. Indeed, this love of speed seems never-ending. Every year motor-cars are produced which go even faster and each new computer boasts (吹嘘) of saving precious seconds in handling tasks.

All this saves time, but at a price. When we lose or gain half a day in speeding across the world in an airplane, our bodies tell us so. We get the uncomfortable feeling known as jet-lag; our bodies feel that they have been left behind in another time zone. Again, spending too long at computer results in painful wrists and fingers. Mobile phones also have their dangers, according to some scientists; too much use may transmit harmful radiation into our brains, a consequence we do not like to think about.

However, what do we do with the time we have saved? Certainly not relax, or so it seems. We are so accustomed to constant activity that we find it difficult to sit and do nothing, or even just one thing at a time. Perhaps the days are long gone when we might listen quietly to a story on the radio, letting imagination take us into another world.

There was a time when some people’s lives were devoted simply to the cultivation of the land or the care of cattle. No multi-tasking there; their lives went on at a much gentler pace, and in a familiar pattern. There is much that we might envy about a way of life like this. Yet before we do so, we must think of the hard tasks our ancestors faced: they farmed with bare hands, often lived close to hunger, and had to fashion tools from wood and stone. Modern machinery has freed people from that primitive existence.

小题1: The new products become more and more time-saving because       .

A.the manufacturers boast a lot

B.time is limited

C.the prices are increasingly high

D.our love of speed seems never-ending小题2: What does “the days” in Paragraph 3 refer to?

A.Simple life in the past.

B.Imaginary life.

C.Times of inventions.

D.Time for constant activity.小题3:. What is the author’s attitude towards the modern technology?

A.Critical.

B.Optimistic.

C.Objective.

D.Negative.小题4:. What does the passage mainly discuss?

A.The present and past times.

B.Modern technology and its influence.

C.Imaginations and inventions.

D.Machinery and human beings.

问答题 简答题