问题 选择题

在一密闭容器中加入A、B、C三种气体,保持一定温度,在t1~t4时刻测得各物质的浓度如下表.据此判断下列结论正确的是(  )

A.在t3时刻反应已经停止

B.A的转化率比B的转化率低

C.在t2~t3内A的平均反应速率为: [1/(t3-t2)]mol/(L·s)

D.在容器中发生的反应为:2A+B2C

答案

答案:C

题目分析:A.根据表格的数据可知在t3时刻反应已经达到平衡状态,但是反应仍然在进行,错误;B.物质的平衡转化率A的转化率是4÷6="2/3;" B的转化率是2÷5.所以A的比B的高,错误;C.在t2~t3内A的平均反应速率为:V(A)="(3-2)" mol/L÷(t3-t2) s=[1/(t3-t2)]mol/(L·s),正确;D.物质在参加化学反应时,物质的物质的量浓度变化比等于方程式中该物质的系数比,所以在容器中发生的反应为:2A+BC,错误。

单项选择题
阅读理解

Welcome to the future. It’s year 2050 and Scotland is now powered completely by“clean”energy.

Homes have entire roofs made of solar materials, rooms are kept warm by wallpaper, and people go to and from work in electric and hydrogen( 氢) cars.

Oil is still being found in the North Sea, but it’s not now only used to keep aircraft flying. And a new 500---mile underwater link with Iceland has been built to catch heat from the hot springs. There’s still a role for king coal—but the black diamonds are now environment---friendly. 

People will be able to import the electricity they need and export any excess(超过的量) they make through rooftop windmills(风车). New technology will store electricity better and provide it on demand. Heat exchangers will provide heating and hot water.

Harmful carbon dioxide waste is being piped offshore to St Fergus and from there into some of the remaining oil—producing fields to be stored safely without entering the atmosphere. Gas remains the preferred energy source of industry and is now shipped in liquid form. But hydrogen is imported through pipelines from France and from a geothermal (地热的) plant in Iceland.

Hydrogen—fuelled cars have become popular. Electric bikes are common in cities using the new urban two—wheel network. Electric vehicles have become common, and their performances have been improved because of the developments in electrical drive technology like high—temperature super conducting motors. Many people leave their vehicles in a giant park where they can be recharged from the national electrical system . Oilseed rape (油菜) is widely grown to fuel some motors .

小题1:What does the underlined phrase in paragraph 2 mean ?

A.The hot springs

B.Oil

C.Coal

D.Oil and coal小题2:Which sources of energy play a more important role in people’s daily life in the future ?

A.Oil and coal

B.Hydrogen and gas

C.Electricity and gas

D.Solar energy and wind小题3:The means of transport people use in 2050 do not include__________.

A.windmills

B.electric bikes

C.hydrogen—fuelled cars

D.aircraft小题4:The passage is written to tell us in the future_____________.

A.life will be better and better

B.the energy will become cleaner and cleaner

C.people will use some new sources of energy

D.people will pay more attention to the environment