题目

今有如下三个热化学方程式： (1)H2(g)＋O2(g)===H2O(g) ΔH1＝a kJ·mol－1 (2)H2(g)＋O2(g)===H2O(l) ΔH2＝b kJ·mol－1 (3)2H2(g)＋O2(g)===2H2O(l) ΔH3＝c kJ·mol－1 下列关于它们的叙述正确的是( ) A．它们都是吸热反应 B．a、b和c均为负值 C．a＝b D．2b＝c>0 答案：答案 B 解析 题中所给三个热化学方程式均为放热反应，a、b、c均为负值；1mol H2(g)充分燃烧生成液态水时比生成气态水时放出的热量多，故a>b；2mol H2(g)充分燃烧生成液态水时放出的热量是1mol H2(g)充分燃烧生成液态水时放出的热量的2倍，故c＝2b<0。阅读理解,判断对错,对的打“√”，错的打“×”。 Look at my home. It’s not big. But it’s very nice. There is a living room, a bathroom, a kitchen and two bedroomsMy bedroom is small but clean.I have a bed, a shelf,a desk and a chair .There are many books on the shelf.There is a computer on the desk.I play computer games on Sundays. （1）My home is very big. （2）I have 2 bathrooms in my home. （3）There is a bed,a shelf,a desk and a chair in My bedroom. （4）I play computer games on Mondays. （5）The computer is in the living room.