问题 填空题

根据要求写出下列反应的热化学方程式

(1)一定量氢气与氯气反应生成氯化氢气体,当生成1mol氢氯键时放出91.5kJ的热量________________________________________________________.

(2)某化学反应的能量变化如图所示,该反应的热化学方程式是(反应热用abc表示)

_____________________________________________.

(3)某反应的平衡常数如果有1molN2完全反应,要吸收热量68kJ.写出该反应的热化学方程式______________________________________________.

(4)实验中不能直接测出石墨和氢气生成甲烷反应的反应热,但可测出甲烷、石墨、氢气燃烧的反应热:

CH4(g)+2O2(g)=CO2(g)+2H2O(l);△H1=-890.3kJ/mol

C(石墨,s)+O2(g)=CO2(g) ;ΔH2="-393.5" kJ/mol

H2(g)+1/2O2(g)=H2O(l) ;△H3="-285.8" kJ/moL

则由石墨与氢气反应生成甲烷的热化学反应方程式为__________________________________________.

答案

单项选择题 A1型题
单项选择题

Most people would be (1) by the high quality of medicine (2) to most Americans. There is a lot of specialization, a great deal of (3) to the individual, a (4) amount of advanced technical equipment, and (5) effort not to make mistakes because of the financial risk which doctors and hospitals must (6) in the courts if they (7) things badly.

But the Americans are in a mess. The problem is the way in (8) health care is organized and (9) . (10) to pubic belief it is not just a free competition system. The private system has been joined a large public system, because private care was simply not (11) the less fortunate and the elderly.

But even with this huge public part of the system, (12) this year will eat up 84.5 billion dollars—more than 10 percent of the U. S. Budget—large number of Americans are left (13) . These include about half the 11 million unemployed and those who fail to meet the strict limits (14) income fixed by a government trying to make savings where it can.

The basic problem, however, is that there is no central control (15) the health system. There is no (16) to what doctors and hospitals charge for their services, other than what the public is able to pay. The number of doctors has shot up and prices have climbed. When faced with toothache, a sick child, or a heart attack, all the unfortunate persons concerned can do is (17) up. Two thirds of the population (18) covered by medical insurance. Doctors charge as much as they want (19) that the insurance company will pay the bill.

The rising cost of medicine in the U. S. A. is among the most worrying problems facing the country. In 1981 the country’s health bill climbed 15.9 percent--about twice as fast as prices (20) general.

19()

A. knowing

B. to know

C. they know

D. known