题干

250℃和1.01105Pa时,反应:2N2O5(g)="4NO2(g)+O2(g)" △H=+56.76kJ/mol,自发进行的原因是

A:是吸热反应

B:是放热反应

C:是熵减少的反应

D:熵效应大于焓效应

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答案(点此获取答案解析)

D

同类题1

阅读下列短文,然后从每小题A、B、C、D 中选出能回答所提问题或完成所给句子的最佳答案。    

    Some people believe that schools will no longer be necessary in the near future. They said that because of the Internet and other new technology, there is no longer any need for school buildings, classes or teachers. Perhaps this will be true one day, but if the world has no schools, I can't imagine how our society will be. In fact, we should learn how to use new technology to make schools better. We should invent a new kind of school that is linked to libraries, museums, science centers, labs and even companies. Technological companies should create(创造) learning programs for schools. Scientists or professors could give talks through the Internet. TV networks and local stations could develop programs about things students are actually studying in school. Labs could set up websites to show new technology so students could see it on the Internet.

    Is this a dream? No. There are already many cities where this is beginning to happen. Here the whole city is linked to the Internet, and learning can take place at home, at school, and in the office. Businesses provide programs for the schools and the society. The schools provide computer labs for people without their own computers at home. Because everyone can be on the Internet, older people use it as much as younger ones. And everyone can visit distant(远处的) libraries and museums as easily as nearby ones. How will this new kind of school change the usual way of learning? It is too early to be sure, but it is very exciting to think about it. Technology will change the way we learn; schools will change as well; and we will all learn something from the Internet.