题目

Ⅰ．二甲醚是一种重要的清洁燃料，可以通过CH3OH分子间脱水制得：2CH3OH(g) CH3OCH3(g) ＋ H2O(g) ΔH＝－23.5kJ·mol－1。在t1℃，恒容密闭容器中建立上述平衡，体系中各组分浓度随时间变化如图所示。(1)该条件下反应平衡常数表达式K＝______________；在t1 ℃时，反应的平衡常数为____________，达到平衡时n(CH3OCH3)：n(CH3OH)：n(H2O)=_____________________。(2)相同条件下，若改变起始浓度，某时刻各组分浓度依次为：c(CH3OH)＝0.4 mol·L－1、c(H2O)＝0.6 mol·L－1、c(CH3OCH3)＝2.4mol·L听短文，填词，听两遍。    John is a middle school student. He likes music very much. He knows a lot about country music,1            music and pop music. Of course he sings pretty well. His favorite 2            is Jay Zhou. He thinks Jay Zhou is very cool, although he doesn't sing the words 3           . And he likes musicianswho can write their own 4           . He 5            energetic music to quiet music. He thinks music is a part of his life and he wants to be a famous musician some day in the future.