问题
填空题
除去一氧化碳中的二氧化碳应用______试剂；除去壶胆上的水垢应用______试剂．
答案
二氧化碳气体可与碱溶液反应，而一氧化碳气体不与碱反应，所以可把混合气体通过澄清石灰水或氢氧化钠溶液而除去混合气体中的二氧化碳；水垢的主要成分碳酸钙和氢氧化镁会和酸溶液发生反应，能溶于酸溶液，所以一般用酸溶液来除水垢．
故答案为：Ca（OH）2 ；HCl．
搜题请搜索小程序“爱下问搜题”
除去一氧化碳中的二氧化碳应用______试剂；除去壶胆上的水垢应用______试剂．
二氧化碳气体可与碱溶液反应，而一氧化碳气体不与碱反应，所以可把混合气体通过澄清石灰水或氢氧化钠溶液而除去混合气体中的二氧化碳；水垢的主要成分碳酸钙和氢氧化镁会和酸溶液发生反应，能溶于酸溶液，所以一般用酸溶液来除水垢．
故答案为：Ca（OH）2 ；HCl．
任务型阅读 Now you’ve finished three years of English study. There’s one way to demonstrate(展示)what you’ve learned-take a test! Do you have any special methods(方法) you use to help you do better on a test? How well you do is often a matter of how well prepared you are. Here are some ways to make sure you’re at your best on test days. Go to bed early. The night before a test is not the time to stay up watching TV. You want to be rested and wide-awake for test day. Have a good breakfast. Test day isn’t a morning for donuts(面包圈).Nor is it a time to starve yourself. Eat plenty of low-sugar, high-energy food to keep your brain and body working their best. Be prepared, Make sure you have two pencils and anything else you were asked to bring. Watch the numbers. Make sure that the number of the items(项目)on your answer sheet matches the number of the question. Look over all the answer choices(选择). Don’t assume(假定)that choice A is correct until you’ve checked the others. You may find a better one. And it is wrong to eliminate(排除)any choice that you can see at once. You’ll have a better chance of finding the right answer. Check the clock. Make sure you allow yourself enough time to answer every question and go back and check your answers .Don’t spend too much time on any difficult question .Skip(跳读)it and come back to it later. Keep up with your school work all year long That’s how you get the skills you need for taking tests.
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