何谓水玻璃？其模数如何表示？如何控制水玻璃的模数？ -题库考试答案搜索网

何谓水玻璃？其模数如何表示？如何控制水玻璃的模数？

问答题

2021-12-28 03:31

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正确答案

水玻璃：是各种聚硅酸盐水溶液的通称。
模数：钠水玻璃中SiO2和Na2O的物质的量之比称为模数，用M表示：
M=nSiO2/nNa2O=1.033wSiO2/wNa2O
WSiO2和WNa2O分别为硅酸钠中SiO2和Na2O的质量分数。
1）降低模数：可适当加入NaOH，提高水玻璃中Na2O的质量分数。反应式为：
Si（OH）4+2NaOH—Na2O•SiO2•H2O+2H2O
2）提高模数：则可加入HCl，NH4Cl等，以中和部分Na2O，反应式为：
Na2O•mSiO2•nH2O+2HCl--mSiO2•nH2O+2NaCl+H2O
Na2O•mSiO2•nH2O+2HCl+2NH4Cl--mSiO2•（n-1）H2O+2NaCl+2H2O+2NH3

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标签：材料成型工艺学材料科学大学试题理学

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