Question

Способы устранения постоянной жёсткости воды можно условно назвать карбонатным и фосфатным. Запишите уравнения реакций для каждого способа ( 2 уравнения)

Answer 1

CaCL2+Na2CO3=CaCO3+2NaCl
MgCl2+Na2CO3=MgCO3+2NaCl
3CaCL2+2Na3PO4=Ca3(PO4)2+6NaCl
3MgCL2+2Na3PO4=Mg3(PO4)2+6NaCl

Answer 2

Ways to Remove Permanent Hardness of Water

Carbonate Method: The carbonate method involves the use of sodium carbonate (soda ash) to remove the permanent hardness of water. The reaction can be represented as follows: ``` Ca(HCO3)2 + Na2CO3 → 2NaHCO3 + CaCO3 ``` This reaction results in the formation of calcium carbonate, which is insoluble and can be easily removed from the water, thus reducing the hardness.

Phosphate Method: The phosphate method utilizes sodium hexametaphosphate to eliminate the permanent hardness of water. The reaction can be expressed as: ``` Ca(HCO3)2 + Na6P6O18 → 6NaHCO3 + Ca3(PO4)2 ``` In this reaction, calcium phosphate is formed, which is insoluble and can be separated from the water, effectively reducing its hardness.

These methods provide effective ways to address the issue of permanent hardness in water, ensuring that it is suitable for various applications.