烧碱在空气中久置会变质，写出有关反应的化学方程式______，在部分变质后的物质中，加入足量盐酸，写出有关反应的化学方程式：
______，______．
烧碱是氢氧化钠的俗称，在空气中久置能与空气中的二氧化碳反应生成碳酸钠而变质，反应的化学方程式为2NaOH+CO2═Na2CO3+H2O；部分变质后的物质中含有氢氧化钠和碳酸钠，加入足量盐酸，均能与稀盐酸反应；碳酸钠与稀盐酸反应生成氯化钠、水和二氧化碳，反应的化学方程式为：Na2CO3+2HCl═2NaCl+H2O+CO2↑；氢氧化钠与盐酸反应生成氯化钠和水，反应的化学方程式为：NaOH+HCl═NaCl+H2O．
故答案为：2NaOH+CO2═Na2CO3+H2O；Na2CO3+2HCl═2NaCl+H2O+CO2↑；NaOH+HCl═NaCl+H2O．
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| Flies (苍蝇) usually live in the dirty places. Let's look at a fly, and see where it 1 . First, it flies out of the window, 2 it stands on 3 dirty things in the street, and then it flies back to the house and walks over your 4 . When a fly walks on the dirty things in the street, its 5 have got some germs 6 them. When the fly walks on your food with its dirty feet, it 7 the germs on your food. What can you 8 this? First, we learn that we mustn't leave dirty things in the street or on the ground near 9 . Second, we learn that all food must be covered so that flies may not 10 it. Third, we learn that flies often carry germs and we must kill them as soon as we see them. | ||||
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