问题 推断题

A、B、C、D均为4种常见的短周期元素,原子序数依次增大,A、C能组成分子式为A2C2和A2C两种常见的化合物,它们在常温下都 是液体;B与A既可形成分子X,也可形成阳离子Y,X、Y都是10电子的粒子;D 在同周期中原子半径最大。

(1)D元素在周期表中的位置是____;D的单质在C的单质中燃烧生成固体W的电子式为____; 液态X类似A2C,也能微弱电离且产生电子数相同的两种离子,则液态X电离方程式为____。

(2)将C的单质通入1 mol/L KI和0.1 mol/L H2SO4混合溶液中,反应的离子方程式为____。

(3)M、N分别是由A、B、C、D四种元素中的其中三种元素组成的强电解质。M 的水溶液呈碱性,它能抑制水的电离;N的水溶液呈酸性,它能促进水的电离。则M、N分别为___、____(填化学式);若将0.1 mol/L的M 和0.2 mol/L的N两溶液等体积混合,所得溶液中离子浓度的大小顺序为____。

答案

(1)第三周期第IA族 ;Na2O2 ;2NH3NH4++NH2-

(2)4H++4I-+O2=2I2+2H2O

(3) NaOH ;NH4NO3 (或NH4NO2 )  ;c(NO3-) [或c(NO2-)>c(NH4+)>c(Na+)>c(OH-)>c(H+)

单项选择题
单项选择题

It was a ruling that had consumers seething with anger and many a free trader crying foul. On November 20th the European Court of Justice decided that Tesco, a British supermarket chain, should not be allowed to import jeans made by America’s Levi Strauss from outside the European Union and sell them at cut-rate prices without getting permission first from the jeans maker. Ironically, the ruling is based on an EU trademark directive that was designed to protect local, not American, manufacturers from price dumping. The idea is that any brand-owning firm should be allowed to position its goods and segment its markets as it sees fit: Levi’s jeans, just like Gucci handbags, must be allowed to be expensive.

Levi Strauss persuaded the court that, by selling its jeans cheaply alongside soap powder and bananas, Tesco was destroying the image and so the value of its brands—which could only lead to less innovation and, in the long run, would reduce consumer choice. Consumer groups and Tesco say that Levi’s case is specious. The supermarket argues that it was just arbitraging the price differential between Levi’s jeans sold in America and Europe—a service performed a million times a day in financial markets, and one that has led to real benefits for consumers. Tesco has been selling some 15,000 pairs of Levi’s jeans a week, for about half the price they command in specialist stores approved by Levi Strauss. Christine Cross, Tesco’s head of global non-food sourcing, says the ruling risks "creating a Fortress Europe with a vengeance".

The debate will rage on, and has implications well beyond casual clothes (Levi Strauss was joined in its lawsuit by Zino Davidoff, a perfume maker). The question at its heart is not whether brands need to control how they are sold to protect their image, but whether it is the job of the courts to help them do this. Gucci, an Italian clothes label whose image was being destroyed by loose licensing and over-exposure in discount stores, saved itself not by resorting to the courts but by ending contracts with third-party suppliers, controlling its distribution better and opening its own stores. It is now hard to find cut-price Gucci anywhere.

Brand experts argue that Levi Strauss, which has been losing market share to hipper rivals such as Diesel, is no longer p enough to command premium prices. Left to market forces, so-so brands such as Levi’s might well fade away and be replaced by fresher labels. With the courts protecting its prices, Levi Strauss may hang on for longer. But no court can help to make it a great brand again.

Which of the following is not true according to Paragraph 1 ()

A.Consumers and free traders were very angry

B. Only the Levi’s maker can decide the prices of the jeans

C.The ruling has protected Levi’s from price dumping

D. Levi’s jeans should be sold at a high price