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问题 实验题

某学习小组探究浓、稀硝酸氧化性的相对强弱，按下图装置进行实验（夹持仪器已略去）。实验表明浓硝酸能将NO氧化成NO2，而稀硝酸不能氧化NO。由此得出的结论是浓硝酸的氧化性强于稀硝酸。 可选药品：浓硝酸、3 mol/L稀硝酸、蒸馏水、浓硫酸、氢氧化钠溶液及二氧化碳 已知：氢氧化钠溶液不与NO反应，能与NO2反应。

2NO2 +2NaOH =NaNO3+ NaNO2+ H2O

（1）实验应避免有害气体排放到空气中。装置③、④、⑥中盛放的药品依次是__________________

（2）滴加浓硝酸之前的操作是检验装置的气密性，加入药品，打开弹簧夹后_____________________

（3）装置①中发生反应的化学方程式是_________________________ 。

（4）装置②的作用是____ ，发生反应的化学方程式是___________________________

（5）该小组得出的结论所依据的实验现象是______________________ 。

（6）实验结束后，同学们发现装置①中溶液呈绿色，而不显蓝色。甲同学认为是该溶液中硝酸铜的质量分数较高所致，而乙同学认为是该溶液中溶解了生成的 气体。同学们分别设计了以下4个实验来判断两种看法是否正确。这些方案中可行的是（选填序号字母）____。

a．加热该绿色溶液，观察颜色变化

b．加水稀释该绿色溶液，观察颜色变化

c．向该绿色溶液中通人氮气，观察颜色变化

d．向饱和硝酸铜溶液中通入浓硝酸与铜反应产生的气体，观察颜色变化

答案

（1）3 mol/L稀硝酸、浓硝酸、氢氧化钠溶液

（2）通入CO2 一段时间，关闭弹簧夹，将装置⑤中导管末端伸入倒置的烧瓶内

（3）Cu +4HNO3（浓）=Cu(NO3)2 +2NO2↑ +2H2O

（4）将NO2转化为NO；3NO2 +H2O===2HNO3+NO

（5）装置③中液面上方气体仍为无色，装置④中液面上方气体由无色变为红棕色

（6） acd

阅读理解

Directions: Read the following text and choose the most suitable heading from A—F for each paragraph. There is one extra heading which you do not need.
A.  Forecasting Research
B.  Well-known Weather Forecasters
C.  Severe Weather Events
D.  Weather Forecasting
E.  The Forecasting Process
F.  Historical Background
小题1:
The task of predicting the weather that will be observed at a future time is called weather forecasting.  As one of the primary objectives of the science of meteorology, weather forecasting has depended critically on the scientific and technological advances in meteorology that have taken place since the latter half of the 19th century.
小题2:
Throughout most of history, forecasting efforts at any given site depended solely on observations that could be made at the site.  With the development of the telegraph in the mid-1800s, weather forecasters were able to obtain observations from many distant locations within a few hours of the collection of such data.  Weather forecasting was revolutionized in the 1920s by the work of a group of Norwegian scientists.  This group provided a consistent and empirically based description of atmospheric circulation systems.  Current weather-forecasting techniques were initiated by the theoretical work of American meteorologist Jule Charney in developing numerical weather prediction.  Experimental numerical forecasts in 1950 proved so fruitful that they were soon adopted on a practical basis.  Since then, computerized systems based on numerical models have become a central part of weather forecasting.
小题3:
The process of making a weather forecast can be separated into three steps: observation and analysis, extrapolation to find the future state of the atmosphere, and prediction of particular variables.  The standard extrapolation technique is to assume that weather features will continue to move as they have been moving.  In some cases the third step simply consists of noting the results of extrapolation, but actual prediction usually involves considerable efforts beyond this. 
小题4:
Great attention is paid to weather forecasts during times of severe events (blizzard, hurricane and typhoon, tornado), and so forth.  Accordingly, the National Weather Service (NWS) commits significant resources to the forecast of such events.  Blizzards or strong extra-tropical cycles are handled through the usual forecast information channels, with the local NWS office issuing special advisories as appropriate.
小题5:
A number of new observing systems are being developed for forecasting purposes.  These include the Next-Generation Radar digital weather radar, which is intended to detect motions towards or away from the radar installation.  In addition, automated systems are being developed for taking observations at surface stations and on board buoys, ships, and aircraft.  The communications, processing, and display systems intended to govern this torrent of further data are still being elaborated.
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单项选择题

某河段的水体环境容量是指( )。

A．水环境所能承纳的最大的污染物质的负荷量
B．污水容纳总量
C．允许排放的污染物的体积量
D．允许排放污染物的种类
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