问题 问答题

合成氨生产技术的创立开辟了人工固氮的途径,对化学工业技术也产生了重大影响.合成氨反应的化学方程式为:N2(g)+3H2(g)

3NH3(g)△H=-92.2kJ/mol.合成氨工业中原料气N2可从空气中分离得到,H2可用甲烷在高温下与水蒸气反应制得.我国合成氨工业目前的生产条件为:催化剂-铁触媒,温度-400~500℃,压强-30~50MPa.

回答下列问题:

(1)合成氨工业中原料气压缩到30~50MPa的原因是______.从平衡移动原理分析,低温有利于原料气的转化,实际生产中采用400~500℃的高温,原因之一是考虑到催化剂的催化活性,原因之二是______.

(2)500℃、50MPa时,在容积为VL的容器中加入n mol N2、3n mol H2,反应达平衡后测得平衡常数为K,此时N2的转化率为x.则K和x的关系满足K=______.

(3)甲烷在高温下与水蒸气反应反应方程式为:CH4(g)+H2O(g)=CO(g)+3H2(g).部分物质的燃烧热数据如下表:

物  质燃烧热(kJ•mol-1
H2(g)-285.8
CO(g)-283.0
CH4(g)-890.3
已知1mol H2O(g)转变为1mol H2O(l)时放出44.0kJ热量.写出CH4和H2O在高温下反应的热化学方程式______.

(4)有人设想寻求合适的催化剂和电极材料,以N2、H2为电极反应物,以HCl-NH4Cl为电解质溶液制取新型燃料电池.请写出该电池的正极反应式______.

答案

(1)合成氨反应的化学方程式为:N2(g)+3H2(g)

2NH3(g)△H=-92.2kJ/mol,反应物气体的化学计量数大于生成物气体的化学计量数,则加压有利于平衡正向移动,提高原料气的转化率,升高温度虽然不利于平衡向正反应方向移动,但能增大反应速率,缩短达到平衡的时间.

故答案为:加压有利于平衡正向移动,提高原料气的转化率;增加反应速率,缩短达到平衡的时间;         

(2)N2(g)+3H2(g)

2NH3(g)

起始:

n
V
mol/L   
3n
V
mol/L         0

转化:

nx
V
mol/L   
3nx
V
mol/L      
2nx
V
mol/L

平衡:

n(1-x)
V
mol/L
3n(1-x)
V
mol/L
2nx
V
mol/L

k=

(
2nx
V
)2
(
n(1-x)
V
)×(
3n(1-x)
V
)3
=
4xV2
27n2(1-x)4

故答案为:

4xV2
27n2(1-x)4

(3)已知:①H2(g)+

1
2
O2(g)=H2O(l)△H=-285.8kJ•mol-1

②CO(g)+

1
2
O2(g)=CO2(g) )△H=-283.0kJ•mol-1

③CH4(g)+2O2(g)=CO2(g)+2H2O(l))△H=-890.3kJ•mol-1

④H2O(g)=H2O(l)△H=-44.0kJ•mol-1

利用盖斯定律将④+③-②-3×①可得:CH4(g)+H2O(g)=CO(g)+3H2(g)

△H=(-44.0kJ•mol-1)+(-890.3kJ•mol-1)-(-283.0kJ•mol-1)-3×(-285.8kJ•mol-1)=+206.1 kJ•mol-1

故答案为:CH4(g)+H2O(g)=CO(g)+3H2(g)△H=+206.1 kJ•mol-1

(4)N2在正极发生还原反应生成NH4+,电极反应式为N2+6e-+8H+=2NH4+,故答案为:N2+6e-+8H+=2NH4+

名词解释
填空题

Part 1


·Read the.following passages, eight sentences have been removed from the article.
·Choose from the sentences A-H the one whichfits each gap.
·For each gap (1-8) mark one letter (A-H) on the Answer Sheet.
·Do not mark any letter twice.
In the world of entertainment, TV talk shows have undoubtedly flooded every inch of space on daytime television. (1) But no two shows are more profoundly opposite in content, while at the same time standing out above the rest, than the Jerry Springer and the Oprah Winfrey show.
Jerry Springer could easily be considered the king of"trash talk". (2) For example, the show takes the ever-common talk show themes of love, sex, cheating, guilt, hate, conflict and morality to a different level. (3)
Like Jerry Springer, Oprah Winfrey takes TV talk show to its extreme, but Oprah goes in the opposite direction. (4) Topics range from teaching your children responsibility, managing your workweek, to getting to know your neighbors.
Compared with Oprah, the Jerry Springer show looks like poisonous waste being dumped on society. Jerry ends ever with a "final word". (5) Hopefully, this is the part where most people will learn something very valuable.
Clean as it is, the Oprah show is not for everyone. (6) Most of these people have the time, money, and stability to deal with life’s tougher problems. Jerry Springer, on the other hand, has more of an association with the young adults of society. (7) They are the ones who see some value and lessons to be learned underneath the show’s exploitation.
While the two shows are as different as night and day, both have ruled the talk show circuit for many years now. (8) Ironically, both could also be considered pioneers in the talk show world.
  • A. He makes a small speech that sums up the entire moral of the show.
  • B. The show focuses on the improvement of society and an individual’s quality of life.
  • C. The show’s main target audience are middle-class Americans.
  • D. Each one caters to a different audience while both have a p following from large groups of fans.
  • E. The topics on his show are as shocking as shocking can be.
  • F. These are 18-to 20-year-olds whose main troubles in life involve love relationship, sex, money and peers.
  • G. And anyone who watches them regularly knows that each one varies in style and format.
  • H. Clearly, the Jerry Springer show is a display and exploitation of society’s moral catastrophe, yet people are willing to eat up the intriguing predicaments of other people’s lives.