问题
问答题 简答题
如何检验生石灰是否变质，变质的程度怎样？设计实验：写出具体的实验步骤和实验现象。
答案
参考答案：
检验生石灰变质的方法是：取样溶于水，溶液温度升高说明有生石灰存在。向澄清的水溶液中滴加酚酞试液，溶液变红，说明没有完全变质。滴加稀盐酸，有气泡溢出，说明已经部分变质生成碳酸钙。
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如何检验生石灰是否变质，变质的程度怎样？设计实验：写出具体的实验步骤和实验现象。
参考答案：
检验生石灰变质的方法是：取样溶于水，溶液温度升高说明有生石灰存在。向澄清的水溶液中滴加酚酞试液，溶液变红，说明没有完全变质。滴加稀盐酸，有气泡溢出，说明已经部分变质生成碳酸钙。
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| Professor Green, known to the world as a scientist, is not only absent-minded but short-sighted as well. His mind is always busy 1 scientific problems and seldom notices what is going on 2 him. One fine day recently, he went 3 a walk in the countryside, but as 4 he has a book in his hand. When he went out , he began to read his book . He hadn't gone far 5 he run into a big cow and fell down. In the fall, he had lost his glasses, without which he couldn't see anything. He thought he had hit his head 6 a fat lady. "I'm sorry, Madam." He said politely 7 searching for his glasses. As soon as he had 8 , he realized his mistake. Soon he was fixing his mind on his book 9 and paid no attention to anything else. He had scarcely been walking for five minutes when he fell over again, _10 both his book and his glasses. This time he got very angry, seizing his umbrella, he gave the "cow" a wild blow. Then, after finding his glasses, he realized with horror that he made a second mistake. A large fat woman was fleeing from him in a horror. | ||||
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