问题 选择题

如图所示是298K时,N2与H2反应过程中能量变化的曲线图,下列叙述正确的是(  )

A.该反应的热化学方程式为:N2+3H2⇌2NH3 △H=-92 kJ/mol

B.b曲线是加入催化剂时的能量变化曲线

C.升高温度,正反应速率减小,逆反应速率增大,平衡逆向移动

D.在温度、体积一定的条件下,通入1 mol N2和3 mol H2充分反应后放出的热量为92 kJ

答案

A、该反应放出的能量大于吸收的能量,所以放热,书写热化学方程式必须标注物质的聚集状态,该热化学方程式未标注物质的状态,故A错误;

B、催化剂能改变反应的路径,使发生反应所需的活化能降低,即可降低生产能耗,故B正确;

C、升高温度,正逆反应速率都增大,增大程度不同,平衡逆向移动,故C错误;

D、反应是可逆反应,在温度、体积一定的条件下,通入1 mol N2和3 mol H2充分反应后放出的热量小于92 kJ,故D错误;

故选B.

单项选择题

Once upon a time, innovation at Procter & Gamble flowed one way: from the United States outward. While the large Cincinnati-based corporation was no stranger to foreign markets, it usually sold them products that were already familiar to most Americans. Many Japanese families, for instance, swaddle their babies in Pampers diapers, and lots of Venezuelans brush their teeth with Crest. And of course (company executives assumed) Americans at home wanted these same familiar, red white-and-blue brands. We might buy foreign-made cars, or chocolates, or cameras—but household cleaners and detergents.9

Recently, however, P&G broke with this long-standing tradition. Ariel, a P&G laundry detergent, was born overseas, and is a familiar sight on store shelves in Europe and Latin America. Now bilingual packages of Ariel Ultra, a super-concentrated cleaner, are appearing on supermarket shelves in Los Angeles.

Ariel’s appearance in the United States reflects demographic changes making Hispanics the nation’s fastest-growing ethnic group. Ariel is a hit with this population. In fact, many Mexican immigrants living in southern California have been " importing" Ariel from Tijuana, Mexico. "Hispanies knew this product and wanted it," says P&G spokeswoman Marie Salvado. "We realized that we couldn’t convince them to buy our other laundry detergents. " P&G hopes that non-Hispanic consumers will give Ariel a try too.

Ariel’s already p presence in Europe may provide a springboard for the company to expand into other markets as well. Recently P&G bought Rakona, Czechoslovakia’s top detergent maker. Ariel, currently a top seller in Germany, is likely to be one of the fast new brands to appear in Czech supermarkets. And Ariel is not tile only foreign idea that the company hopes to transplant back to its home territory. Cinch, an all-purpose spray cleaner similar to popular European products, is currently being test-marketed in California and Arizona. Traditionally Americans have used separate cleaners for different types of surfaces, but market research shows that American preferences are becoming more like those in other countries.

Insiders note that this new reverse flow of innovation reflects more sweeping changes at Procter & Camble. The firm has hired many new Japanese, German, and Mexican managers who view P&G’s business not as a one-way flow of American ideas, but a two-way exchange with other markets. Says Bonita Austin of the investment fin Wertheim Schroeder, " When you met with P&G’s top managers years ago, you wouldn’t have seen a single foreign face; today, they could even be in the majority. "

As Procter & Gamble has found, the United States is no longer an isolated market. Americans are more open than ever before to buying foreign-made products and to selling U S-made products overseas.

The author may most probably agree that()

A. it is a trend that businesses today go global

B. businesses today are very reluctant to go global

C. American businesses can make more money if they only sell home-made products

D. the market of the United States should not be that open

问答题 简答题