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正、V逆都发生变化，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正______，V逆______（选填：增大、减小、不变）V正变化的倍数______V逆变化的倍数（选填：大于、小于、等于）
（3）降温，V正、______V逆______（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．
plane, 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.
ax, or so it seems. We are so accustomed to constant activity that we find it difficult to sit and d
o 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.
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.