题干

下列说法正确的是(  )


A:H2(g)的燃烧热△H=﹣285.8 kJ/mol,则2H2O(g)═2H2(g)+O2(g)△H=+571.6 kJ/mol

B:反应物的总能量低于生成物的总能量时,该反应为放热反应

C:由石墨比金刚石稳定可知:C(金刚石,s)=C(石墨,s)△H<0

D:已知:298 K时,N2(g)+3H2(g)⇌2NH3(g)△H=﹣92.0 kJ/mol.在相同温度下,向密闭容器中通入0.5 mol N2和1.5 mol H2,达到平衡时放出46.0 kJ的热量

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C

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     Qi Haoran, a Junior Grade One student at a High School Attached to Harbin Institute of Technology, was quite busy over the past winter holiday – and not just with homework. Qi, together with 10 other classmates made a volunteer group to call on people to join the Clean Your Plate Campaign (光盘行动).

     These students went to many restaurants and told people the importance of saving food. “Excuse me, do you know that 950 million people around the world still haven't got enough to eat? Please don't waste food.” They would say this kind of thing hundreds of times every day.

     The Clean Your Plate Campaign began on the Internet in January. It calls on people to reduce food waste. China in recent years has experienced serious problems with wasted food. CCTV reported in January that the food Chinese people waste every year is enough to feed 200 million people for a year.

     Chinese people are well-known for being hospitable(好客的) and generous. Many even feel that they lose face if their guests have eaten all the food.

     Luckily, the campaign has got the support of many. In a restaurant in Xinjiang, the owner gives the guests who have eaten up all that they ordered a sticker(贴花). People can enjoy a free meal when they have 10 stickers. More than 750 restaurants in Beijing have begun to offer smaller dishes and encourage their guests to take leftovers (剩饭剩菜) home.

     To reduce food waste is a big task, and it needs time. It's important that everyone does their bit, just like Qi. Did you finish your meals today?