下列化学方程式符合题意，且书写正确的是（ ）
A．用盐酸除去铁锈 Fe2O3+4HCl═2FeCl2+3H2O
B．验证铜的活动性比银强 Cu+2AgCl═CuCl2+2Ag
C．检验二氧化碳气体 CO2+Ca（OH）2═CaCO3↓+H2O
D．制取少量硫酸镁 MgCl2+Na2SO4═MgSO4+2NaCl
A、铁锈与盐酸反应生成铁盐而不是亚铁盐，正确的方程式为：6HCl+Fe2O3=2FeCl3+3H2O；故A正确；
B、金属与盐反应首先要求盐必须可溶，氯化银不溶于水，故此反应不能发生，故B错误；
C、根据二氧化碳通入澄清石灰水中会使澄清的石灰水变浑浊来检验二氧化碳，故C正确；
D、此反应没有气体、沉淀或水生成，故反应不会发生，故错误；
故选C
Meng Meihui,14,from Dongying, Shandong, loved reading certain pieces of work. But she paid particular attention to her classmate’s every composition, just to find her faults. “Everyone said she was better at writing than me. I didn’t believe it. I wanted to beat her,”Meng said. Meng was caught by the green-eyed monster-jealousy(嫉妒) Jealousy is _____among students. Most people may feel a little bit unhappy when others are better than them. It’s natural. However, if students don’t change theirs mindset(思维方式)and deal with it well, jealousy can bring out many problems. Su Lulu, 14, from Xiamen, Fujian， said those who are too jealous of others might lose _____easily.“Few people like those who always try to find faults in others,” Su said. “A popular student should be open-minded.” Besides affecting students’ interpersonal(人际间的)relationships, jealousy may also limit students’ development. Meng said that during that time, she paid too much attention to her competitor(竞争者)and_______to improve herself. “It was tiring and useless,” she said. Luckily, Meng_____ realized the problem. She stopped her silly behavior and focused on her own progress. Wang Xiao, a psychology(心理学)teacher at Huangshi Foreign Language School, Hubei, agreed with Meng’s practice. Wang said the best way to deal with jealousy is to turn it into motivation(动力) “___those who are better than you and focus on yourself, ” Wang said. “It’s more important to improve yourself than to be better than others.” Wang also suggested that students be confident about themselves. “Everyone has their advantages and disadvantages. Don’t _______your disadvantages with others’ advantages,” he said.
|