问题 填空题

A、B、C、D、F是常见的化合物,其中F在常温下是一种无色液体,D为强酸,请根据下图转化关系(反应条件及部分产物已略去),回答下列问题:

(1)若A、B、C、D均为含硫元素的化合物,A是一种常见的矿石的主要成分,且A的摩尔质量为120。 反应①的化学方程式为                         

(2)若A、B、C、D均为含氮元素的化合物,且A的一个分子中只含有10个电子,则:

①A分子式为__________;

②反应④的离子方程式为________________________________________________ 

③取Cu和Cu2O的混合物样品12.0g,加入到足量的D的稀溶液中,用排水法收集产生的气体,标准状况下其体积为2.24L,则样品中Cu2O的质量为__________g。

答案

(1)4FeS2+11O2Fe2O3+8SO2;(2分)

(2)①NH3 ;(2分)

②3Cu+8H++2NO3-=3Cu2++2NO↑+4H2O;(2分)

③4.32g(2分,4.3也得分)

题目分析:(1)A是一种常见的矿石的主要成分,且A的摩尔质量为120,A是FeS2,E为氧气,则反应①的化学方程式为4FeS2+11O2Fe2O3+8SO2

(2)①A、B、C、D均为含氮元素的化合物,A的一个分子中只含有10个电子,则A是NH3

②E是氧气,B是NO,C是NO2,F是水,D为硝酸,所以反应④的离子方程式为3Cu+8H++2NO3-=3Cu2++2NO↑+4H2O

③设Cu和Cu2O的物质的量分别为x、y,根据得失电子守恒,2.24L/22.4L/mol×3=2x+2y,二者的质量为12.0g,所以有64x+144y=12,解得y=0.03mol,因此Cu2O的质量是0.03mol×144g/mol=4.32g

单项选择题

Modern industrial society grants little status to old people. In fact, such a society has a system of built-in obsolescence. There is no formal system for continuing our education throughout our life in order to keep up with rapidly changing knowledge. When our education and job skills have grown obsolete, we are treated exactly like those who have never gained an education or job skills and are not encouraged or given the opportunity to begin anew.
As a society becomes more highly developed, the overall status of older people diminishes. Improved health technology creates a large pool of old people, who compete for jobs with the young. However, economic technology lowers the demand for workers and creates new jobs for which the skills of the aged are obsolete, forcing older people into retirement. At the same time, young people are being educated in the new technology and are keeping pace with rapid changes in knowledge. Finally, urbanization creates age-segregated neighborhoods. Because the old live on fixed incomes, they must often live in inferior housing. All these factors—retirement, obsolete knowledge and skills, inferior standards of living—lower the status of the aged in society.
A century ago, when one could expect to live only to 50 or so, the life span more or less coincided with the occupation and family cycle. But today the average life span allows for fifteen to twenty years of life after these cycles. It appears that our life span is outpacing our usefulness in society.

According to this passage, the status of the aged is lowered by their ______.

A.forced retirement

B.inferior housing

C.longer life span

D.fixed incomes

选择题