（12分）市场上出售的“热敷袋”其主要成分是铁屑、炭粉和少量的NaCl、水等。热敷袋在启用前用塑料袋使之与空气隔绝，启用时，打开塑料袋轻轻揉搓，就会放出热量，使用完后，会发现袋内有许多铁锈生成。回答:
（1）热敷袋放出的热量来源于_________放出的热量。
（2）炭粉的作用是________________________。
（3）加入NaCl的作用是________________________。
（4）写出有关电极反应式和化学方程式________________。
（ 12 分）（1）铁屑被氧化 （2）C、Fe与NaCl、水组成原电池，C作正极，使铁氧化速率加快 （3）溶于水形成电解质溶液，增强导电性 （4）正极反应:O2+2H2O+4e-====4OH-,负极反应:2Fe-4e-====2Fe2+,发生的反应有
Fe2++2OH-==Fe(OH)2↓,
4Fe(OH)2+O2+2H2O====4Fe(OH)3,
2Fe(OH)3====Fe2O3·xH2O+(3-x)H2O
| Every summer, Jean Piaget retreats to his cabin in the Alps, where he spends most of his days analyzing the mass of research data generated over the past year at his Center for Genetic Epistemology. During long walks along the mountain trails, he mulls over the latest experimental results, and in the cool mountain evenings, he formulates his conclusions. With the approach of fall, he will descend from the mountain, manuscript for a book and several journal articles in hand. This time-honored procedure of careful observation followed by seclusion for thought and synthesis, has enabled him to become the most prolific, if not the most famous psychologist of the century. Piaget has only been widely known in this country since the 1960s, when his works were translated from their original French. But he has been recognized as an expert in the field of cognitive development in Europe since the 1930s. In fact, Piaget’s publishing career can be traced to the year 1906, when as a child of ten, he published his careful notes on the habits of an albino sparrow he observed near his home in Switzerland. After his precocious debut as an ornithologist, he took an after school job at the local natural history museum, soon becoming an expert on mollusks. At the age of sixteen he was recommended for a curator’s position at the natural history museum in Geneva, but declined in favor of continuing his education. He studied natural science at the University of Neuchatel, obtaining his doctorate at the age of twenty-one. His readings in philosophy stimulated an intense interest in epistemology-the study of humans acquire knowledge. Convinced that cognitive development had a genetic basis. Piaget decided that the best way to approach epistemology would be through its behavioral and biological components. Psychology appeared to be the discipline that best incorporated this approach. |
Which of the following statements is true
A．When the weather became cool, he went down the mountain and started writing books and articles.
B．When the weather was hot, he went up the mountain and began writing.
C．When the weather was cool, he took long walks on the mountain trails.
D．He liked to walk in the cool evening, thinking about his experiments.