问题 填空题

氨气(NH3)是一种无色有刺激性气味的气体,极易溶于水.它的水溶液称为氨水,显碱性.氨在化学工业中用途广泛,例如制化肥、制纯碱等;近年来,氨还用于环境治理.

(1)氨分子中氮、氢元素的质量比为______.

(2)氨气中氮元素的化合价为______.

(3)“侯氏制碱法”关键一步的反应原理可表示为:NH3+CO2+H2O+NaCl═NaHCO3+A,其生成物A也可用作化肥,A的化学式为______.

(4)在细菌作用下,用氨处理含甲醇的工业废水,使其变为无毒的N2和CO2,从而清除对环境的污染,有关的反应为:6NH3+5CH3OH+12B═3N2↑+5CO2↑+19H2O,上述反应的B处应填入的物质的化学式是______.

(5)在400℃左右,有催化剂存在的条件下,用氨气可将有毒气体NO还原为N2和H2O,试写出该反应的化学方程式:______.

答案

(1)根据化合物中各元素质量比=各元素的相对原子质量×原子个数之比,可得氨分子中氮、氢元素的质量之比为 14:3;

(2)据化合物中正负元素化合价总数和为0的原则,氨气(NH3)中氢元素的化合价是+1价,所以氮元素的化合价是-3价;

(3)根据质量守恒定律,原子的种类、数目在化学反应前后不变可知反应式:NH3+CO2+H2O+NaCl═NaHCO3+A中生成物A化学式为:NH4Cl;

(4)根据质量守恒定律,原子的种类、数目在化学反应前后不变可知反应式6NH3+5CH3OH+12B═3N2↑+5CO2↑+19H2O中B的化学式为O2

(5)由于在400℃左右,在催化剂存在的条件下,用氨气可将有毒气体NO还原为N2和H2O,依据化学方程式的书写方法,方程式为:4NH3+6NO

催化剂
.
400℃
5N2+6H2O;

故答案为:(1)14:3;(2)-3;(3)NH4Cl;(4)O2;(5)4NH3+6NO

催化剂
.
400℃
5N2+6H2O.

单项选择题
阅读理解

                                    

The small number of newborn babies, which has been caused by high prices and the changing social situation of women, is one of the most serious problems in Asia. When people talk about it, you can hear a word invented in Japan. which means Double Income Kids(小孩).

In many major Asian cities like Seoul, Singapore, and Tokyo, the cost of a ****** is extremely high. A young couple who want to buy their own house may have to pay about $3000,000 (though prices have fallen). For a flat with one bedrooms, one dining-room, a kitchen, and a bathroom, the couple will pay about $900 a month. What’s more, if they want to have a child, the child’s education is very expensive. For example, most kindergarten charges are at least $5.000 a year. In such a situation, it’s difficult to afford children.

The number of married women who want to continue working because they enjoy their jobs. However, if they want to have children, they immediately have serious problems. Though most companies allow women to leave their jobs for a short time to have a baby, they expect women with babies to give up their jobs. In short, if they want to bring up children properly, both parents have to work, but it is hard for mothers to work. Indeed, women who want to contimue working have to choose between having children or keeping their jobs.

In a word, Asian governments must take steps to improve the present situation as soon as possible.

小题1:What is the main problem being discussed in the passage?

A.The small number of newborn babies.

B.The changing social situation of women.

C.The high prices of houses and education.

D.The necessary steps of Asian government.小题2:According to the passage, which of the following is true?

A.It is easy for a couple to afford a child in Asia.

B.The prices of in Asia are quite low now.

C.Fewer and fewer married women wan to have a job.

D.The word “DINKS” appeared in an Asian country.小题3:To buy a flat and send a child to kindergarten, how much will a couple pay each year?

A.85,000

B.85,900

C.$10.800

D.$15.800小题4:The seems to believe that Asian governments should ________.

A.let women stay at home and have a baby

B.allow one of the parents to go out to work

C.care for the growing needs of women for job.

D.the companies that permit women to leave.