论文部分内容阅读
第十五届天原杯复赛试题的26、27题(第四大题,见本期59面)为化学计算题,本文仅对这两题作以点评。 26题以学生熟悉的雷电现象为命题背景,学生阅读题后,应理出以下几条: ①雷电是一种很普遍的自然现象; ②雷电发生时,N_2和O_2发生了化学反应; ③N_2和O_2反应时,质量与能量间的数量关系; ④一次闪电所产生的能量,及这一能量用于N_2和O_2反应时的利用率。这4条中,解题的有效信息为②③④条。再对照题目要求,可以逐步列式解答。解题过程:(1)写出N_2和O_2发生的化学反应方程式:
The 26th and 27th questions of the fifteenth Tianyuan Cup rematch question (the fourth major question, see the 59 faces of the current issue) are chemical calculation questions. This article only commented on these two questions. Question 26 is based on the background of the lightning phenomenon that students are familiar with. After students read the questions, they should devise the following: 1 Lightning is a very common natural phenomenon; 2 When lightning strikes, chemical reactions occur between N_2 and O_2; 3N_2 and In the O 2 reaction, the quantitative relationship between mass and energy; 4 The energy generated by a lightning, and the utilization of this energy for N 2 and O 2 reactions. Of these four items, 234 pieces of information are valid for problem solving. Then with reference to the topic requirements, you can step-by-step solutions. Problem solving process: (1) Write the chemical reaction equations for N_2 and O_2: